OPTICAL FLEX SPECTRUM DETECTOR

Abstract

An optical system may include an optical source for providing excitation light and a collection element for directing an optical signal received from a sample in response to the excitation light being incident on the sample to an optical device. The optical device may include a separation element for separating the optical signal into a plurality of spectral bands spatially or angularly separated along a band separation direction, a dispersive element comprising a dispersive region for dispersing spectral components of a spectral band along a dispersion direction to form a dispersed spectral band, and an optical element for manipulating the dispersed spectral band in association with imaging the spectral band onto a detector area of a detector array.The optical system may include a controller for obtaining one or more readout signals from the detector array.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 620,080, filed January 11, 2024, entitled "FLEX SPECTRUM SPECTROMETRY." The disclosure of the prior application is considered part of this patent application and is incorporated by reference. TECHNICAL FIELD

[0002] The present disclosure generally relates to an optical detector and an optical flex spectrum detector. BACKGROUND

[0003] In spectrometry, a full-spectrum response is conventionally dispersed such that the dispersed spectrum has the form of a continuous elongated beam (with a large width-to-height aspect ratio) formed from dispersed spectral bands. Conventionally, the dispersed spectral bands are arranged in a "linear" one-dimensional (1D) sequence from one edge of a beam to another edge of the beam, either without any discontinuity or with only one spectral band imaged in a direction perpendicular to the direction of dispersion, for each detector pixel position along the direction of dispersion. When performing spectroscopy, it is generally desirable to detect a response from a sample with high sensitivity and high resolution across the full spectrum (e.g.for Raman spectrometers over a spectral range of over 100 nanometers (nm) (in wavelength) or over 3000 reciprocal centimeters (cm. -1 ) (in wavenumbers)). SUMMARY

[0004] In some implementations, an optical system includes an optical source for providing excitation light; a collection element for: directing an optical signal received from a sample in response to incidence of the excitation light on the sample to an optical device; the optical device comprising: a separation element for separatingSeparating the optical signal into a plurality of spectral bands that are spatially or angularly separated along a band separation direction, wherein spectral regions differ between each spectral band of the plurality of spectral bands, a dispersive element comprising a plurality of dispersive regions, wherein a dispersive region of the plurality of dispersive regions is configured to disperse spectral components of a spectral band of the plurality of spectral bands along a dispersion direction to form a dispersed spectral band, a plurality of optical elements, wherein an optical element of the plurality of optical elements is configured to manipulate the dispersed spectral band in association with or in connection with imaging the spectral band onto a or a detector surface or region of a detector array, and the detector array comprising the detector surface; and a controller for obtaining orObtaining one or more readout signals from the detector array.

[0005] In some implementations, an optical system includes an optical source for providing excitation light; a collection element for directing an optical signal received in response to incidence of the excitation light on a sample to an optical device; wherein the optical device is configured to: separate the optical signal into a plurality of spectral bands that are spatially or angularly separated along a band separation direction, wherein each spectral band of the plurality of spectral bands has a different spectral range; disperse spectral components of a spectral band of the plurality of spectral bands along a dispersion direction to form a dispersed spectral band; and image the dispersed spectral band in association with imaging the spectral band onto a detector surface.-region of a detector array of the optical device; and a controller for obtaining one or more readout signals from the detector array.

[0006] In some implementations, an optical system includes an optical source for providing excitation light; a collection element for directing an optical signal received in response to incidence of the excitation light on a sample to an optical device; the optical device comprising: a separating element for separating the optical signal into a plurality of spectral bands; wherein the spectral regions differ between each spectral band of the plurality of spectral bands; a dispersive element comprising a dispersive region, the dispersive region configured to disperse spectral components of a spectral band of the plurality of spectral bands to form a dispersed spectral band; an optical element for imaging the dispersed spectral band in association with imaging the spectral band onto a detector surface.-area of a detector array, and the detector array comprising the detector surface; and a controller for coordinating operation of the optical source with operation of the collection element or one or more elements of the optical device such that a time of reception of the optical signal is synchronized with a time of a detection window of the detector surface. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A-1C are diagrams illustrating examples associated with an optical system including a flex-spectrum optical detector described herein. Fig. Figure 2 illustrates an example associated with an optical device that provides flexible segmentation and arrangement of a full spectrum. Fig. 3 and Fig.4 are graphs associated with an increase in dynamic range and sensitivity as enabled by an optical device described herein. Fig. 5-7 are diagrams illustrating example implementations of a separator described here. DETAILED DESCRIPTION

[0007] The following detailed description of example implementations refers to the accompanying drawings. The same reference numerals in different drawings may refer to the same or similar elements.

[0008] In spectrometry, a spectrograph is conventionally designed to provide light as a single, non-segmented, linear optical beam containing a full spectral range, which is interrogated by the spectrograph at a dispersive element of the spectrograph. The dispersive element disperses the light, and the dispersed light is projected onto a detector of the spectrograph as a continuous, non-segmented, linear image.Here, the dispersed spectrum classically takes the form of a continuous, elongated beam (with a large width-to-height aspect ratio) formed of dispersed spectral components arranged in a "linear" 1D sequence from one edge of a beam to another edge of the beam, either without any discontinuity or with only one spectral component imaged in a direction perpendicular to a direction of dispersion, for each detector pixel position along the dispersion direction. When performing spectroscopy, it is generally desirable to detect a response from a sample with high sensitivity and high resolution over the full spectrum (e.g., for Raman spectrometers, over a spectral range of over 100 nanometers (nm) (in wavelength) or over 3000 reciprocal centimeters (cm). -1) (in wavenumbers)). However, in practice, this is difficult to implement efficiently. For example, if a highly sensitive and high-resolution detector array across a full spectrum is required, the physical design of the detector would have to accommodate a large width-to-height aspect ratio, resulting in an inefficient use of physical space in a spectrometer system. Accordingly, it would be advantageous to discard the conventional 1D shape of the dispersed spectrum and avoid the large aspect ratio of the detector, and be compatible with more typical 2D imaging detector arrays.

[0009] Furthermore, any dispersed spectrum has two important attributes: spectral range and spectral resolution. These attributes are at odds with each other for a fixed physical spectrum width. That is, for a given spectral range, there is a given spectral resolution. Increasing the resolution results in an increased spectral width for a fixed spectral range or a reduced spectral range for a fixed spectral width. These limitations exist for a 1D spectrum imaged on a detector. When performing spectroscopy, it is common for all spectral bands within the full-spectrum response to nominally have the same degree of sensitivity and resolution.However, most conventional spectroscopy systems aim to identify specific characteristics for which one or more particular spectral bands can provide more useful identification information, while other spectral bands can provide minimal identification information. This can lead to poor detector utilization if all spectral bands have the same sensitivity and resolution. Accordingly, it would be advantageous to provide greater sensitivity and resolution for spectral bands that provide more useful identification information and lower sensitivity and resolution for spectral bands that provide less useful identification information. Analogously, some spectral bands of the full spectrum may not provide any useful information at all, and therefore it would be advantageous to avoid imaging these spectral bands on the detector.

[0010] A conventional two-dimensional (2D) technique can be used in some cases to split a full spectrum into multiple beams (e.g., using a beam splitter), each containing the full spectral range. Then, different spectral range portions of each beam are imaged onto different detectors. Note that according to this conventional 2D technique, each beam contains the full spectrum at a fraction of the original power, and only a fraction of different spectral bands from each beam are then imaged onto a detector. This wastes power because the original power is split into each full-spectrum beam, and then the portions of each beam not imaged onto the detector are wasted.Thus, even those spectral regions that are mapped onto a section of the detector contain only a fraction of the original power in that spectral region. Wasted power also reduces sensitivity. Accordingly, it would be advantageous to map as much power as possible from the full spectrum onto the detector.

[0011] Implementations described here provide techniques and apparatus for measuring spectral responses in which a full-spectrum response can be divided into spectral bands (e.g., subspectra of any spectral range, resolution, or dynamic range), and each spectral band can be directed by dispersion and to a desired physical location on a detector array while preserving the power of the full-spectrum response. In other words, the techniques and apparatus described here can be implemented to separate a full-spectral response into a group of distinct spectral bands (e.g., subspectra) in wavelength or wavenumber with minimal power loss, and these spectral bands can then be independently manipulated or rearranged prior to spectral dispersion and imaging onto a detector (e.g., a 2D detector).The techniques and devices described here avoid power loss when splitting the full-spectrum response; decouple the bandwidth, resolution, and dynamic range limitations for each spectral band; increase the efficiency with respect to the use of a 2D detector and enable a more compact spectrograph.

[0012] The techniques and devices described here enable a comparatively more compact spectrograph by separating a full spectrum of incident light into spectral bands without any loss of power (apart from power loss caused by non-idealities of optical components that perform the separation function) and spatially rearranging the spectral bands (e.g., in a stack) before forwarding the spectral bands to a dispersive element. Such a design can enable higher optical resolution per spectral band from the dispersive element and, in some designs, allow a reduced size of the dispersive element in a dispersion direction. After dispersion, the dispersed spectral bands are projected and imaged onto a 2D detector array (e.g.,in a stack), enabling higher detector resolution and increasing the efficiency in terms of using an active area of the detector array.

[0013] The techniques and devices described herein involve spectral banding at a front end that splits a full spectral region prior to dispersion into multiple spectral bands (e.g., a set of adjacent, consecutive, or distinct spectral regions). In some implementations, the spectral bands may not overlap, or may partially (e.g., minimally) overlap, or may have almost no overlap (e.g., to allow for redundancy or manufacturing tolerance when attempting to create non-overlapping or adjacent spectral bands). In some implementations, the spectral bands may be rearranged in space and stacked onto a dispersive element in a non-dispersive direction (e.g., a direction perpendicular to the dispersion direction), creating a 2D array of spectral bands. In some implementations, the dispersive element may have multiple dispersive regions (e.g.,(each with different dispersive properties) that can be assigned to the spectral bands incident on it. Each dispersive region of the dispersive element can thus disperse and redirect the light incident on it independently of the other dispersive regions.

[0014] After dispersion, the spatial arrangement of the dispersed spectral bands can be maintained or further rearranged while directing the dispersed spectral bands onto a detector array. In some implementations, for example, the dispersed spectral bands can be arranged in space and stacked onto a 2D detector array in a band separation direction. The spectral bands can be rearranged in different ways (e.g., depending on the chosen spectral range bins and resolution targets). In general, the number of spectral bands, the spectral ranges of the spectral bands, and the spectral resolutions of the spectral bands can be freely and independently adjusted according to a desired performance target for a given application (e.g., Raman, time-gated Raman, spatially offset Raman spectroscopy (SORS), fluorescence, or the like).For example, a spectrum formed from the sum of all spectral bands may be discontinuous (e.g., interrupted by one or more gaps) or may have different spectral resolutions for different subspectra. Additionally or alternatively, the dynamic range and sensitivity desired for measuring each spectral band can be freely adjusted and independent of the other spectral bands by controlling and / or regulating the "height" (e.g., in a direction orthogonal to the dispersion direction) at which each spectral band is imaged onto the detector.While increasing the detector area illuminated by a particular spectral band does not change the total amount of photons in that spectral band, increasing the detector area increases the dynamic range that can be achieved for that spectral band and increases a saturation limit of the detector for wavelengths in that spectral band because the photons are spread across more pixels of the detector. In some implementations, the techniques and devices described here enable the removal of one or more spectral bands (e.g., one or more spectral bands that are not of interest). For example, one or more spectral bands can be removed from an image on the detector during spectrum splitting, during dispersion, or during spatial or angular rearrangement (e.g., before or after dispersion).

[0015] It should be noted that the techniques and devices described here enable full-spectrum segmentation in a different way than the conventional 2D technique described above. In some implementations, the full spectrum is divided into spectral bands located at different wavelengths / wavenumbers, which are then spatially rearranged to create a 2D array in which multiple spectral bands (which together cover the full spectral range and may contain nearly all of the power of the original spectrum) are stacked in a direction perpendicular to the dispersion direction. With such an array, higher resolution can be achieved compared to a 1D array (i.e., on a 1D detector) of the same width.For comparison, achieving the same full spectral range with increased resolution using a linear 1D response would require a detector with a spectral dispersion dimension increased by a factor equivalent to the number of generated spectral bands (e.g., assuming that all spectral bands have the same width and cover the same spectral range). Compared to the conventional 2D technique, the power loss is minimal because the full spectrum has been divided into separate, (optionally) non-overlapping spectral bands that contain almost all of the full spectrum's power. This flex-spectrum spectrometry technique allows for maximum utilization of the active area of a detector, which can be a rectangular 2D detector array (e.g., with a low width-to-height ratio).In some implementations, the full spectrum can be separated into separate non-overlapping spectral bands that are spatially rearranged to be stacked in alignment with an active area of a low-aspect ratio 2D detector array.

[0016] For the same physical size as a conventional 1D solution, the techniques and devices described here can achieve higher resolution and / or cover a wider spectral range. Alternatively, the techniques and devices described here can achieve the same performance with a reduced width of the detector in the dispersion direction, which is typically the largest dimension of the detector used in spectrometry, at a fraction of the physical size of the conventional 1D technique. Segmenting the spectrum to reduce the width while adding height from the rearrangement of the segmented spectral bands in a direction perpendicular to the dispersion direction (i.e., the band separation direction) results in an advantageous detector geometry in terms of enabling a spectrometer or spectrometry system with a compact size (e.g.,volume) or in terms of compatibility with a wider range of commercially available detector arrays with large pixel counts (e.g., SPAD arrays). Adding detector height to cover the additional spectral bands results in little or no increase in spectrometer height, whereas reducing detector width results in a significant reduction in footprint due to lower angular dispersion of the dispersed subspectra and their smaller width at a single detector plane. As a result of the reduced detector width, the sizes of optical and mechanical components within the spectrometer are also reduced, resulting in a reduction in the size, weight, and (potentially) power consumption of the spectrometer system.

[0017] As described above, the techniques and devices described herein can achieve higher resolution and / or cover a larger spectral range for a given detector width along the dispersion direction. Performance attributes of a spectrometer are no longer fixed or limited by the detector width. Adding a second dimension to the spectral array enables this flexibility. The techniques and devices described here enable varying the detection dynamic range and sensitivity across the full spectral range. Because the spectrum is segmented, each spectral band can be adjusted to cover a specific height (i.e., a number of pixels in the band separation direction) on an active area of the detector.Therefore, the detection dynamic range and sensitivity (which scales with the height of a spectral component on the active area of the detector) can be modulated across the different spectral bands, for example to account for the relative importance of the different spectral bands in a spectrometry measurement.

[0018] In practice, a spectrograph can be used, for example, in a Raman spectroscopy application that utilizes a time-gating principle. The time-gating principle in Raman spectroscopy is used to suppress sample-induced fluorescence and phosphorescence during the measurement process and maintain a sufficiently high signal-to-noise ratio (SNR) while suppressing other potential continuous interference (e.g., ambient light, thermal emissions, or the like). Time-gated Raman spectroscopy is an effective technical solution to the problem of sample-induced fluorescence, which could mask a Raman signal during spectral detection.Conventional optical systems for performing time-gated Raman spectroscopy use a conventional spectrograph implementing the 1D technique described above and therefore suffer from a power-to-size trade-off arising from the way the light is manipulated (e.g., dispersion into a single, non-segmented, linear optical beam containing the full spectral range; and projection as a continuous, non-segmented, linear image onto a detector). As noted above, for the same dispersion performance, this technique requires a wide dispersive element (in the dispersion direction) to achieve a given spectral resolution, and, furthermore, a wide detector area to cover the full spectral range for a given spectral range and resolution.As an alternative to the wide detector area, to cover the full spectral range for a given spectral range and resolution, an angle of incidence at the dispersive element can be stepped or scanned and the spectrum can be sequentially assembled using a comparatively smaller 1D detector array.

[0019] In some implementations, the compact spectrograph described herein may be included in an optical system used in a time-gated Raman spectroscopy application or another type of spectroscopy application, such as a time-resolved fluorescence spectroscopy application, a dynamic spatially offset real-time Raman spectroscopy (SORS) application, a laser-induced breakdown spectroscopy (LIBS) application, or a photoacoustic spectroscopy application, among other examples. In general, for a given application, the number of spectral bands provided by the spectrograph can be varied, and a spectral range and / or spectral resolution of a given spectral band can be adjusted freely and independently of other spectral bands. In this way, the optical system may be capable of meeting a performance target for the optical system in a given application.Further details are described below.

[0020] Fig. 1A-1C are diagrams illustrating examples associated with an optical system 100 including a flex-spectrum optical detector 110 described herein. As in Fig. 1A, the optical system 100 may include an optical source 102, a collection element 104, a filter 106, a slit 108, the optical flex spectrum detector 110 (referred to herein as optical device 110), and a controller 122. As illustrated, depending on a design of the optical system 100, the optical system 100 may include one or more other elements associated with manipulating or directing light, such as one or more directing elements (e.g., one or more mirrors) or one or more lenses (in Fig.1A). In one example, the optical system 100 includes a compact Raman spectroscopy engine that can be used in a desktop, handheld, or embedded application. In some implementations, one or more elements of the optical system 100 may be contained in a hermetic package. In one example implementation, elements of the optical system 100 other than the optical source 102 may be housed in a hermetic package. The hermetic package may, for example, be a sealed metal housing. In some implementations, the hermetic sealing may improve reliability of one or more elements of the optical system 100, such as a collection element 104 in the form of a MEMS device or a thermoelectric cooler (TEC) used for laser cooling (in Fig.1A not shown), among other examples. Furthermore, in some implementations, hermetic sealing can improve wavelength stability of the grating dispersion (i.e., calibration).

[0021] The optical source 102 includes one or more elements for providing excitation light 150. In some implementations, the optical source 102 may be a pulsed laser source. In some implementations, the optical source 102 may provide the excitation light 150 such that the excitation light 150 comprises optical pulses with a high repetition rate (e.g., greater than about 500 kilohertz (kHz)), low energy (e.g., less than about 100 nanojoules (nJ)), and a narrow linewidth (e.g., less than about 0.1 nanometers (nm)) for a given wavelength. In some implementations, the wavelength of the excitation light 150 may be approximately equal to 532 nm. In practice, however, the optical source 102 may be configured to provide excitation light 150 at any practical wavelength. In some implementations, the optical source 102 may be capable of reducing the temporal jitter.reduce the temporal variation in the excitation light 150, or may be capable of synchronization to account for the jitter in the excitation light 150. That is, in some implementations, the optical source 102 may be a low-jitter laser source. The optical source 102 may be controlled and / or regulated by the controller 122 to achieve the above-mentioned functions.

[0022] In some implementations, the optical source 102 may be a plurality of optical sources 102, wherein each of the plurality of optical sources 102 is configured, for example, to emit at a different wavelength, to generate excitation light 150 with different pulse characteristics (e.g., pulse width, repetition rate, pulse energy, or the like), or to operate in a different mode of operation (e.g., continuous wave (CW), Q-switched, mode-locked, or the like). In some implementations, as in Fig.1A, the excitation light 150 is provided such that the excitation light 150 is incident on a sample 155. In some implementations, the use of a plurality of optical sources 102 may serve to better utilize a spectral range detected by the optical system 100. In Raman spectroscopy, for example, there is a "silent region" in the Raman shift spectrum, which is typically in a range of about 1800 cm -1 up to about 2800 cm -1In some of these applications, a (second) optical source 102 may provide a different excitation wavelength to fill that spectral band with Raman shifts from a spectral range of interest. Different excitation wavelengths have different interactions with sample material and, in turn, affect important measurement parameters in different ways, such as Raman scattering efficiency, the amount of fluorescence background generated, the damage threshold, and the like. Thus, a combination of multiple optical sources 102, each providing a respective (narrowband) excitation light 150, may be used to enhance the optical system 100 for a given application. In some implementations, an optical source 102 of the optical system 100 may be contained in a hermetic package that houses or accommodates one or more other elements of the optical system 100.An optical source 102 within the hermetic package may, for example, be advantageous to achieve an implementation in which integration of the optical system 100 (e.g., in a single package) is desirable. Additionally or alternatively, an optical source 102 of the optical system 100 may be located outside a hermetic package that houses one or more other elements of the optical system 100. In such an implementation, the optical source 102 may be housed in a second hermetic package (i.e., in a hermetic package separate from the one that houses the one or more other elements of the optical system 100). An optical source 102 outside the hermetic package may, for example, be advantageous to facilitate thermal management (e.g.,since the optical source 102 may be a primary heat source of the optical system 100) to facilitate the replacement or interchange of optical sources (e.g., with another optical source 102 of a different laser type or with a different characteristic) or to increase flexibility in laser design.

[0023] The collection element 104 includes one or more elements for directing an optical signal 160 received from the sample 155 in response to the excitation light 150 being incident on the sample 155 toward the optical device 110. For example, the collection element 104 may include one or more reflective elements, such as one or more MEMS (microelectromechanical systems) mirrors. In some implementations, a collection element 104 in the form of a MEMS mirror may be used to sample pulses of the excitation light 150 across a 1D or 2D region of the sample 155 or to fluctuate the excitation light 150 to avoid damaging or heating the sample 155. In some implementations, the collection element 104 may be omitted from the optical system 100 (i.e., some implementations of the optical system 100 may not include the collection element 104).In one example of such an implementation, the excitation light 150 may be transmitted through the filter 106 to be incident on the sample 155, and the optical signal 160 from the sample 155 may be reflected by the filter 106 on the optical path toward the optical device 110.

[0024] The filter 106 includes one or more elements to remove one or more excitation wavelengths from the optical signal 160. As in Fig. For example, as shown in Figure 1A, the filter 106 may include an element that reflects light at the excitation wavelength (e.g., 532 nm) and transmits light at other wavelengths.

[0025] The slit 108 includes one or more elements associated with defining (in combination with the optical device 110) an optical throughput and optical resolution of the optical system 100. In some implementations, the slit 108 is a mechanical feature such as an opening (e.g., a rectangular opening) in a barrier grating. In some implementations, the optical signal 160 is focused by one or more other elements of the optical system 100 to maximize transmission of the optical signal 160 through the slit 108.

[0026] It should be noted that the Fig. 1A are for illustrative purposes only and other implementations are possible. For example, on a Fig.1A, the excitation light 150 is reflected by the filter 106 and directed by the collecting element 104 onto the sample 155. Furthermore, on a beam path of the optical signal 160, as shown in Fig. 1A, the optical signal 160 is reflected by the collection element 104, transmitted through the filter 106, and directed by a reflective element toward the optical device 110. In this example, the collection element 104 and the filter 106 lie on both the optical signal 160 path and the excitation light 150 path. However, in another example implementation, the optical signal 160 path and the excitation light 150 path may be separate, independent optical paths.

[0027] The optical device 110 includes an optical flex spectrum detector as described herein. Fig.1B is a diagram illustrating an example implementation of the optical device 110. As in Fig. 1B, the optical device 110 comprises a separation element 112, a dispersive element 114, a plurality of optical elements 116 (e.g., comprising an optical element 116a, an optical element 116b, and an optical element 116c), and a detector array 118 comprising a set of detector surfaces 120 (e.g., detector surface 120a, detector surface 110b, detector surface 120c). The upper diagram in Fig. 1B illustrates an example of a view of the optical device 110 along a dispersion direction (i.e., a direction along which the dispersive element 114 disperses spectral bands 165, as described below), while the lower diagram in Fig.1B illustrates an example of a view of the optical device 110 along a band separation direction (i.e., a direction along which the separation element 112 separates the optical signal 160 into a plurality of spectral bands 165, as described below). As in Fig. 1B, the optical signal 160 from the sample 155 (e.g., a modified transmitted signal from the optical source 102, a signal generated by the sample 155 as a result of excitation by the excitation light 150, or the like) includes spectral information (e.g., a spectral response) directed to the optical device 110.

[0028] The separation element 112 includes one or more elements for separating the optical signal 160 into a plurality of spectral bands 165. That is, the separation element 112 includes one or more elements that segment the spectral response of the sample 155 (e.g., by spectral range) and rearrange it (e.g., spatially / angularly) into spatially and / or angularly rearranged spectral bands (e.g., spectral band 165a, spectral band 165b, spectral band 165c, and spectral band 165d). In some implementations, the direction along which the separation element 112 spatially or angularly separates the optical signal 160 into the plurality of spectral bands 165 is referred to as the band separation direction. In some implementations, the band separation direction is perpendicular to a dispersion direction (e.g., a direction along which the dispersive element 114 disperses the spectral bands 165).It should be noted that while the band separation direction perpendicular to the dispersion direction may be used for practical purposes, in some implementations, a geometry may be used where the band separation direction is not perpendicular to the dispersion direction (e.g., depending on a detector geometry). In some implementations, the separation of the optical signal 160 (e.g., the segmentation and rearrangement of the spectrum) is performed in a single direction—the band separation direction. For example, the separation element 112 may change an angle of wavelengths of the optical signal 160 to create a continuous spatial spectrum propagating in the band separation direction.

[0029] The separator 112 may be configured to provide any number of spectral bands with different properties (e.g., physical size and orientation in space, spectral range, and / or spectral width). In some implementations, the spectral ranges differ between each spectral band 165 of the plurality of spectral bands 165. In some implementations, the spectral bands 165 within the plurality of spectral bands 165 may substantially not overlap (e.g., such that each spectral band 165 covers a substantially different frequency range). Such an implementation may, for example, be used to maximize a spectral range covered by the banding of the optical signal 160 provided by the separator 112. In some such implementations, an overlap between a given pair of adjacent spectral bands 165 may be small (e.g.,a maximum overlap in a range of about 2% to about 10%). Such overlap may be used, for example, to avoid gaps between spectral bands 165 that might otherwise arise due to design or manufacturing non-idealities. Additionally or alternatively, spectral bands 165 may substantially overlap in the plurality of spectral bands 165 (e.g., an overlap in the frequency domain that is greater than about 10%) to provide significant spectral redundancy. For example, an application may require that the same subband spectral range (e.g., an overlap of about 100%) be detected by two different detector areas 120 of the detector array 118 (e.g.,if the two detector surfaces 120 have different detector properties, if a power in each “identical” spectral band 165 is intentionally made different upon incidence on a respective dedicated detector surface 120, or the like).

[0030] In some implementations, the separation element 12 may be configured such that the optical power differs between spectral bands 165 (e.g., such that an optical power of a given spectral band 165 is controlled and / or regulated to a desired degree or intentionally differs from an optical power of another spectral band 165). Such an implementation may be used, for example, when different detector surfaces 120 have different optical input power saturation levels (or thresholds) and it is desirable for the different detector surfaces 120 to behave similarly. As another example, such an implementation may be used when using a detector surface 120 with different input power levels is desirable in order to examine the detector surface 120 in different optical input power saturation regimes (e.g.,several spectral bands 165 with the same spectral range, but with different optical power, could be sent to several nominally identical detector surfaces 120).

[0031] In some implementations, the separator 112 may segment the optical signal 160 into spectral bands with no power loss (e.g., except for power losses caused by component non-idealities). It should be noted that conventional techniques are based on power splitting rather than spectral separation. In other words, the conventional techniques split an optical signal into N (N > 1) approximately equivalent sub-beams, with each sub-beam having 1 / N-th of the power from each spectral band of the full spectrum. Conversely, the separation provided by the separator 112 separates the optical signal 160 into the plurality of spectral bands 165 with all the power from its respective band and no power from the other bands (within reasonable component non-idealities).Accordingly, the separation provided by the separation element 112 preserves the power relevant to each spectral band, enabling increased throughput and thereby higher sensitivity. Additionally, preserving the power relevant to each spectral band enables increased measurement speed for spectrometry. For example, the SNR for a given detected spectral component (e.g., a Raman peak within a portion of the spectrum) for a given detection time (i.e., photon collection time) is approximately proportional to the square root of the number of detected Raman photons.For a given excitation pulse energy and a given number of excitation pulses (or equivalently, a given detection time window), comparatively more Raman photons reach the detector within this spectral component, and therefore, a higher SNR is achieved with spectral splitting (compared to power splitting). This means that for the same SNR, spectral splitting requires a smaller number of pulses and thus a reduced detection time window, which is equivalent to an increase in measurement speed.

[0032] The dispersive element 114 comprises one or more elements for dispersing spectral components of the spectral bands 165 to form dispersed spectral bands 165. That is, the dispersive element 114 comprises one or more elements that disperse the spectral bands 165 (e.g., the spectral bands 165a to 165d) to form a plurality of dispersed spectral bands 165 (e.g., dispersed spectral band 165a, dispersed spectral band 165c, and dispersed spectral band 165d in the Fig.1B). In some implementations, the dispersive element 114 may include one or more elements capable of spatially separating incoming light into different spectral components (e.g., wavelengths). For example, the dispersive element 114 may include a diffraction grating, a prism, or another wavelength-dispersive element. In one example implementation, the spatially separated spectral bands 165 are incident on a diffraction grating having spatially separated sections (which may or may not be contiguous), each section configured to operate on the corresponding incident spectral band 165. In some implementations, the direction along which the dispersive element 114 disperses a spectral band 165 is referred to as the dispersion direction. In some implementations, the dispersive element 114 includes a plurality of dispersive regions (e.g.,to disperse a respective one of the plurality of spectral bands 165). In some implementations, the plurality of dispersive regions may be stacked along the band separation direction (e.g., perpendicular to the dispersion direction). In some implementations, a given dispersive region of the dispersive element 114 disperses a spectral band 165 incident thereon independently of the dispersion by other dispersive regions of the dispersive element 114. For example, in some implementations, the plurality of dispersive regions may be monolithically patterned (or mechanically tiled) on a single dispersive element 114, with each dispersive region having a respective (e.g., different) set of dispersive properties.

[0033] In operation, the dispersive element 114 serves to physically separate spectral components that form a given spectral band 165 such that the spectral components of the given spectral band 165 exit the dispersive element 114 at different angles and positions to form a dispersed spectral band 165. In some implementations, the dispersive regions of the dispersive element 114 may operate differently on each spectral band 165 to create dispersed spectral bands 165 with different optical properties (e.g., physical size and orientation in space, spectral range, spectral width, spectral resolution, or the like). For example, a given dispersive region of the dispersive element 114 may angularly and spatially segment or separate a continuous spatial spectrum into individual bands.In some implementations, the dispersive element 114 may define a spectral range of a given spectral band 165.

[0034] The plurality of optical elements 116 includes one or more elements for manipulating the dispersed spectral bands 165 in association with imaging the spectral bands 165 onto detector surfaces 120 of the detector array 118. In some implementations, the plurality of optical elements 116 includes an imaging subsystem for spectral bands 165 to be imaged onto the detector array 118. In some implementations, the plurality of optical elements 116 includes a plurality of elements capable of manipulating a position, a size, and / or an orientation / direction of spectral bands 165 to image one or more spectral bands 165 from the plurality of spectral bands 165 onto the detector array 118 and with a particular arrangement (e.g., as dictated by the size of the detector array 118 and / or performance attributes and / or functional criteria).For example, a given optical element 116 may include one or more lenses, prisms, wedges, mirrors, diffraction gratings, bulk optics, or the like, as well as combinations thereof. In some implementations, a given optical element 116 may maintain one or more properties (e.g., a spectral range, a spectral resolution, a detection dynamic range and sensitivity, a physical size, or a position on a plane of the detector array 118, or the like) of a given spectral band 165 and map such properties to a particular detector surface 120 of the detector array 118. Additionally or alternatively, a given optical element 116 may modify one or more properties of a given spectral band 165.For example, an optical element 116 may be configured to fill a width of the detector array 118 to achieve highest resolution and / or to determine a height of the detector array 118 used for each respective spectral band 165 (e.g., to control and / or regulate dynamic range and sensitivity). In some implementations, the plurality of optical elements 116 may serve to arrange the dispersed spectral bands 165 to optimize utilization of the detector array 118 (e.g., to maximize an area utilized on the detector array 118, to maximize optical resolution, to utilize a specific detector area 120 on the detector array 118 for a specific spectral band 165, or the like).For example, the plurality of optical elements 116 may expand the dispersed spectral bands 165 to match a width of the detector array 118 and stack each spectral band 165 into detector surfaces 120 with respective heights on the detector array 118. In some implementations, the plurality of optical elements 116 may manipulate the dispersed spectral band 165 (e.g., align, steer, focus, collimate, converge, expand, or the like) such that images of the spectral bands 165 are stacked along the band separation direction on a plane of the detector surface 120. For example, in some implementations, the plurality of optical elements 116 may provide spatial rearrangement of the plurality of spectral bands 165 on a plane of the detector surface 120. In some implementations, an optical element 116 in the plurality of optical elements 116 may manipulate a dispersed spectral band 165 such that (e.g.,B. expand) such that a size of the dispersed spectral band 165 along the dispersion direction matches a size of a detector surface 120 along the dispersion direction (e.g., an area of the detector array 118 onto which the spectral band 165 is to be imaged). Analogously, in some implementations, the optical element 116 can manipulate (e.g., expand) the dispersed spectral band 165 such that a size of the dispersed spectral band 165 in the band separation direction matches a size of the detector surface 120 along the band separation direction. In this way, the spatial arrangement of the dispersed spectral bands 165 at the detector surface 120 can be controlled and / or regulated to maximize the use of a particular detector geometry (e.g., a rectangular 2D detector array 118).

[0035] The detector array 118 includes one or more detector surfaces 120 on which one or more of the spectral bands 165 are imaged. In some implementations, as in Fig.1B, the detector surface 120 may comprise a plurality of detector surfaces 120 stacked along the band separation direction. In some implementations, the detector array 118 may comprise a 2D array (e.g., a 2D array of detector surfaces 120). Additionally or alternatively, the detector array 118 may comprise a plurality of 1D detector arrays (e.g., a plurality of 1D detector arrays stacked along the band separation direction). Such an implementation may, for example, extend detection capabilities (e.g., spectral range, spectral resolution, detection dynamic range, detection sensitivity, or the like) of the optical device 110. In some implementations, the detector array 118 may comprise a single-photon avalanche diode (SPAD) array (e.g., a high dynamic range, high sensitivity, and high temporal resolution (sub-nanosecond) SPAD array).Additionally or alternatively, the detector array 118 may include an array of time-resolved photon counting detectors (e.g., an array of areas capable of assigning a timestamp to each photon detected by a given area). Such detectors may also be referred to as time-binned photon counting detectors or time-tagged photon counting detectors. Alternatively, the detector array 118 may include a detector array including photon detectors using a different type of technology (e.g., an array of photon detectors that may or may not include time-resolved photon counting detectors). In some implementations, a size of a first detector area 120 of the plurality of detector areas 120 differs from the size of a second detector area 120 of the plurality of detector areas 120. In some implementations, a detector area 120 of the detector array 118 may be used for multiple spectral bands 165.The reuse of a detector area 120 may be enabled, for example, by multiplexing in the time domain in combination with an active element capable of selecting a spectral band 165 to be manipulated and imaged onto the given detector area 120 at a given time.

[0036] In some implementations, a size of a first detector area 120 of the detector array 118 in the dispersion direction matches a size of a second detector area 120 of the detector array 118 in the dispersion direction, and a size of the first detector area 120 in the band separation direction differs from a size of the second detector area 120 in the band separation direction. In such an implementation, greater sensitivity is provided for a spectral band 165 imaged onto the first detector area 120 with the comparatively larger size. In this way, the dynamic range and sensitivity desired for measuring each spectral band 165 can be freely adjusted independently of the other spectral bands 165 by controlling and / or regulating the "height" in the band separation direction with which each spectral band 165 is imaged onto the detector array 118.While increasing the size of the detector area 120 illuminated by a particular spectral band 165 does not change the total amount of photons in that spectral band 165, the increase in size increases the dynamic range and sensitivity that can be achieved for that spectral band 165 (e.g., by reducing the effect of a preset "dead time" that occurs after a pixel detection event in SPAD arrays) and increases the saturation limit of the detector array 118 for wavelengths in that spectral band 165 because the photons are spread across more pixels of the detector array 118. In some implementations, a given detector area 120 of the detector array 118 may be associated with a different respective spectral band 165. In some implementations, a given detector area 120 may include multiple pixels in the dispersion direction and multiple pixels in the separation direction (e.g.,to avoid saturation and allow more detector counts per pulse, to improve signal quality, or the like). In some implementations, the pixels of a given detector area 120 may be grouped into a plurality of macropixels (e.g., to accommodate a tradeoff between detection efficiency and spectral resolution).

[0037] In some implementations, the arrangement of the spectral bands 165 on the detector surfaces 120 of the detector array 118 can be controlled and / or regulated (e.g., dynamically) such that a particular spectral band 165 is incident on a particular detector surface 120, or such that the particular spectral band 165 is incident in a detector surface 120 that is remote from a particular detector surface 120. For example, the spectral bands 165 can be arranged such that a spectral band 165 of particular interest is incident on a detector surface 120 corresponding to a first row of the detector array 118 to enable "fast" reading from the detector array 118. In some implementations, the detector surface 120 can support segmentation into specific pixel blocks with a programmable readout time per pixel block.As another example, if a particular pixel of the detector array 118 is experiencing noise or other performance issues, the spectral band 165 of particular interest may then be arranged to be incident on a detector face 120 that is not proximate to the particular pixel experiencing the performance issue. In some implementations, arrangements of the spectral bands 165 on the detector faces 120, as described in the examples above, may be dynamically configured, meaning that the arrangement of the spectral bands 165 on the detector faces 120 may be updated, modified, or changed during operation of the optical device 110 (e.g., based on control and / or regulation signals provided by the controller 122).In some implementations, such dynamic control and / or regulation may be achieved, for example, by adjusting a position, orientation, rotation, or other characteristic of one or more elements of the optical system 100, such as the collection element 104, the filter 106, the separation element 112, the dispersive element 114, one or more optical elements 116, the detector array 118, one or more detector surfaces 120, and / or one or more other elements associated with manipulating or directing light (e.g., one or more directing elements, one or more lenses, or the like) in the optical system 100.

[0038] In the Fig.1B, the separation element 112 provides four spectral bands 165 (i.e., four sub-spectra), three of which (e.g., spectral band 165a, spectral band 165c, and spectral band 165d) are directed to the dispersive element 114 to be dispersed and then manipulated by the respective optical elements 116 for imaging with three different geometries (e.g., different heights of each spectral band 165). An example of a resulting arrangement of the optical signal 160 into these three spectral bands 165 with different properties (e.g., height-dependent dynamic range and sensitivity, spectral range, covered spectral width, spectral resolution) is shown in Fig.1B and in Table 1 below. It should be noted that in this example, spectral band 165b is not imaged at detector array 118. That is, in some implementations, at least one spectral band 165 of the plurality of spectral bands 165 may not be imaged on any detector surface 120 of detector array 118. Such an implementation may be used, for example, when some portion (e.g., spectral band 165b) of the full spectrum does not need to be measured or detected. In some implementations, the ability to have such spectral gaps in detection at detector array 118 may enable improvement in one or more other attributes of the detected spectral bands 165 (e.g., increased resolution, redundancy, readout speed, or the like).Thus, in some implementations, a spectrum formed by a sum of a set of spectral bands 165 imaged on the detector array 118 is discontinuous (e.g., it includes one or more spectral gaps). In some implementations, an optical power of a given spectral band 165 of the plurality of spectral bands 165 at the detector array 118 is more than 90% of an optical power of the spectral band 165 before the separation element 112. That is, spectral bands 165 can be imaged on the detector array 118 with no or minimal power loss (apart from power loss caused by non-idealities of optical components performing the separation function).

[0039] It should be noted that since the spectral bands 165 can be stacked when imaged onto the detector array 118 (e.g., a 2D detector array), a required angular range of elements and optics of the optical device 110 in the dispersion direction is significantly reduced (e.g., compared to a conventional device using a comparatively longer 1D detector). This reduces the physical size of the optical device 110, enabling a more compact optical engine. Furthermore, the optical device 110 can be applied to many existing spectroscopy techniques. For example, the optical device 110 can be used for Raman and fluorescence spectroscopy, and the read time of the detector array 118 can be time-gated and / or correlated with exposure of the sample 155 to the excitation light 150.

[0040] Furthermore, according to the techniques described herein, in some implementations, a given spectral band 165 may be directed to any detector face 120 of the detector array 118. An active area of the detector array 118 need not have the same dimension as an area given by a sum of areas of all spectral bands 165 to be detected at the plane of the detector array 118. In some implementations, the spectral bands 165 may be arranged to match a width of the active area of the detector array 118, and a scanning mechanism may be used to move the spectral bands 165 in the band separation direction so that they fall on the detector face 120, or to move the detector array 118 in the band separation direction so that it falls within the field of view of the desired spectral band(s) 165. This may allow the use of a detector array 118 with reduced size (e.g.a 1D array with reduced size or a 2D array with fewer detector areas) whose width is determined by the width of a single spectral band 165 to measure the full spectrum (e.g. a sum of all spectral bands 165).

[0041] In some implementations, one or more elements of the optical device 110 may be configured statically (e.g., using conventional optics). Additionally or alternatively, one or more elements of the optical device 110 may be dynamically configured to dynamically configure, for example, the number of spectral bands 165 generated, a spectral range of each spectral band 165, a dynamic range and sensitivity (or height on the detector array 118) applied to each spectral band 165, and / or a position at which each spectral band 165 is imaged on the detector array 118. A dynamic configuration may allow different spectral bands 165 from different pulses to be imaged onto the detector array 118.In some implementations, a readout of one or more detector areas 120 of the detector array 118 may be performed using a variety of techniques, such as using a global shutter or a rolling shutter. Furthermore, in some implementations, one or more spectral bands 165 may be removed by the separator 112 (e.g., as shown in FIG. Fig. 1B). Additionally or alternatively, one or more other elements of the optical device 10 may be configured to remove one or more spectral bands 165 (e.g., such that the one or more spectral bands 165 are not imaged onto the detector array 118), such as the dispersive element 114 or one or more optical elements 116.

[0042] An optical resolution is given by the dispersive element 114 (e.g., a grating resolution) regardless of the characteristics of the detector array 118. A detector resolution is given by the detector array 118 (e.g., a pixel size of the detector array 118) and, analogously, is independent of the dispersive element 114. The system resolution combines the optical resolution and the detector resolution. For the optical device 110, a best result that can be achieved is the optical resolution, because even if better detector resolution is provided, the detector array 118 cannot sample with a higher resolution than through the dispersed spectral bands 165 provided by the dispersive element 114. In practice, one goal is to match the detector resolution to the optical resolution to avoid degradation of the optical resolution without having unnecessary pixels.In some implementations, a spectral resolution of a first spectral band 165 of the plurality of spectral bands 165 differs from a spectral resolution of a second spectral band 165 of the plurality of spectral bands 165.

[0043] A spectral range is defined by the range of wavenumbers or wavelengths contained in a particular spectral response, signal, band, or subspectra. The spectral range is analogous to a bandwidth in wavelengths. In the case of Raman spectroscopy, an example spectral range of the optical signal 160 may be more than about 100 nm (wavelength) or more than about 3000 cm -1(wavenumber). Furthermore, an example spectral range of a given spectral band 165 may be between approximately 400 and 700 wavenumbers. In some implementations, a spectral range of the first spectral band 165 of the plurality of spectral bands 165 may differ from a spectral range of a second spectral band 165 of the plurality of spectral bands 165.

[0044] The dynamic range is a range of values that can be reported by a set of pixels of the detector array 118 with respect to a particular wavelength / wavenumber in a spectral band 165. In some implementations, increasing the number of pixels per wavelength / wavenumber can increase the dynamic range for that wavelength / wavenumber (e.g., by reducing the impact of the reset "dead time" that occurs after a pixel detection event in SPAD arrays).

[0045] With reference to Fig.1A, the controller 122 is an element for obtaining one or more readout signals from the detector array 118. A readout signal is a signal corresponding to a set of photons detected by a given detector area 120 of the detector array 118 during an acquisition window associated with the given detector area 120. Here, each detector area 120 may be associated with a respective spectral band 165, and therefore, a readout signal associated with a given detector area 120 may correspond to a set of photons for the spectral band 165 associated with the given detector area 120 for a given time window. In some implementations, in connection with obtaining one or more readout signals, the controller 122 may be configured to coordinate operation of the optical source 102 and operation of one or more other elements of the optical system 100.For example, the controller 122 may be configured to coordinate operation of the optical source 102 and operation of the detector array 118 such that a timing of receipt of an optical signal 160 (in the form of optical pulses or photon bursts) from the sample 155 in response to the excitation light 150 provided by the optical source 102 is synchronized with a timing of a detection window of one or more detector surfaces 120 of the detector array 118 from which one or more readout signals are to be obtained. In some implementations, such coordination may involve one or more other elements of the optical system 100.For example, in the case of a collection element 104 that includes a mechanically movable mirror or a shutter, the controller 122 may be configured to control and / or regulate the collection element 104 to enable scanning or dithering of the excitation light 150 across a region of the sample 155. As another example, the controller 122 may be configured to control and / or regulate a scanning element (e.g., a mechanically movable mirror) that enables a direction of the optical signal 160 to the one or more detector surfaces 120 during the acquisition window. In some implementations, this scanning element may be separate from the collection element 104 (e.g., the scanning element may be included in the optical device 110 on the detection optical path after the slit 108).Such an implementation may be used, for example, when the optical signal path 160 and the excitation light path 150 are separate independent paths, or when the optical signal path 160 and the excitation light path 150 share a subset of optical elements of the optical system 100. Alternatively, in some implementations, the sampling element may be included or integrated with the collection element 104 (e.g., the collection element 104 may enable both the sampling or dithering of the excitation light 150 across a region of the sample 155 and the direction of the optical signal 160 to the one or more detector surfaces 120, as controlled and / or regulated by the controller 122).Such an implementation can be used, for example, when the collecting element 104 is located both on the beam path of the optical signal 160 and on the beam path of the excitation light 150.

[0046] In practice, separating Raman and fluorescence signals requires synchronization and timing with sub-nanosecond resolution, meaning that signal delays must be taken into account. Such signal delays can result, for example, from laser cavity dynamics causing a delay or jitter between electrical drive signals and emission of optical pulses, from a propagation delay of transmitted optical pulses to and from the sample 155, from a detection time (e.g., SPAD time bins) relative to the arrival of the laser pulse at the detector array 118, or from a photon detection activation time.In some implementations, the controller 122 may be configured to adjust (optimal) operating parameters and synchronization with sampling or attenuating elements of the optical system 100 to avoid undesirable effects such as damage or heating of the sample 155 (which may change or shift the measured spectrum), detector saturation, or photofading (which may change the measured spectrum).

[0047] In some implementations, the controller 122 may receive a plurality of readout signals, each readout signal being received during a different acquisition window of a plurality of acquisition windows. That is, in some implementations, the controller 122 may be configured to read one spectral band 165 at a time from the detector array 118 (e.g., in a rolling window fashion). In some implementations, the controller 122 may control and / or regulate lengths of a given acquisition window such that lengths may differ among the plurality of acquisition windows. For example, a time period of a first acquisition window associated with a first readout signal may differ from a time period of a second acquisition window associated with a second readout signal. In this way, a time period used to measure a given spectral band 165 may be controlled and / or regulated (e.g.,relative to others) to enable improved measurement for comparatively higher priority spectral bands 165. Additionally or alternatively, the controller 122 may receive a plurality of readout signals, each readout signal being received simultaneously during a single acquisition window (e.g., in the manner of a global shutter).

[0048] In some implementations, the controller 122 may be configured to coordinate a sampling of a readout signal of the one or more readout signals with an excitation of the sample 155 to enable time-resolved Raman spectroscopy. Additionally or alternatively, the controller 122 may be configured to coordinate a temporal sampling of a readout signal of the one or more readout signals with an excitation of the sample 155 to enable time-resolved fluorescence spectroscopy. Thus, in some implementations, the optical system 100 may be configured for use in, for example, a time-gated Raman spectroscopy application (e.g., time-resolved measurement and temporal discrimination of Raman and fluorescence signals), a time-resolved fluorescence spectroscopy application (e.g.,Fluorescence lifetime imaging spectroscopy (FLIM) or the like), a dynamic real-time SORS application, a LIBS application, or a photoacoustic spectroscopy application, among other examples.

[0049] In some implementations, the controller 122 may be configured to perform synchronization to account for temporal jitter in the excitation light 150. For example, in some implementations, the controller 122 may use a separate optical detector to detect a timing of pulses of the excitation light 150 and control and / or regulate a timing of the detector array 118 accordingly. In some implementations, such synchronization may be performed in addition to or alternatively to the temporal jitter control and / or regulation performed by the optical source 102.

[0050] In some implementations, the optical system 100 may include one or more other elements that are Fig. 1A-1B are not shown. For example, in some implementations, the optical system 100 may include a sensing element to dither or sample the excitation light 150 incident on the sample 155. In one example, the sensing element may be a MEMS device with 1D or 2D sensing capability. In some implementations, the sensing element may be integrated with the collection element 104. In some implementations, such a sensing element could also be used to disable the laser output, meaning that the sensing element does not provide sampling but is "parked" in a position (or state) that prevents the excitation light 150 from exiting an enclosure of the optical system 100.

[0051] As another example, in some implementations, the optical system 100 may include a translation element to dynamically adjust a spatial separation between an illumination optical path of the optical system 100 (e.g., a path through which the excitation light 150 is provided to the sample 155) and a detection optical path of the optical system 100 (e.g., a path through which the optical signal 160 is provided to the optical device 110). In one example, a translation element may be included (e.g., within the optical system 100 or in an external inspection attachment) and may be used to enable dynamic, spatially resolved Raman and fluorescence spectroscopy. With such a capability, the illumination optical path and / or the detection optical path may be dynamically translated on the sample 155.This dynamic change in the separation between the illumination beam path and the detection beam path enables the investigation of Raman and fluorescence signals from different depth layers of the sample 155 and provides measurement capabilities and attributes analogous to those of the SORS technique, while also allowing a dynamic change in the position of the investigated surfaces or layers of the sample 155. In some such implementations, the translation element may be integrated with the collection element 104 and / or with a sampling element configured to dither or sample the excitation light 150 incident on the sample 155, or it may be a separate element.

[0052] As another example, in some implementations, the optical system 100 may include a scanning interface mounted on a hermetic package that houses one or more elements of the optical system 100 (e.g., the optical device 110). In some implementations, the scanning interface may enable, for example, a fiber probe, an optical relay system (e.g., for adjusting beam size and working distance), or an external SORS application.

[0053] In some implementations, the optical system 100 described herein differs from conventional solutions in that the optical system 100 enables (1) simultaneous time-resolved measurement and temporal discrimination of Raman and fluorescence, (2) increased sensitivity and measurement speed, (3) increased resolution and spectral range, (4) improved size, weight, and power (SWAP), (5) reduced sample damage, and (6) extension to dynamic spatially shifted Raman spectroscopy.

[0054] With regard to point (1), when an optical pulse is incident on a material, both Raman and fluorescence signals are generated. While Raman scattering has a short lifetime (e.g., on the order of sub-picoseconds (ps)), the fluorescence process involves true electronically excited states with finite measurable lifetimes (e.g., on the order of many ps to microseconds (µs)). Thus, when using optical pulses as the excitation source, Raman and fluorescence signals can be separated in the temporal domain. In some implementations, a time-resolved measurement and temporal discrimination of Raman and fluorescence signals by the optical system 100 can be achieved through the use of a detector array 118 in the form of a 2D SPAD array detector with high sensitivity and high temporal resolution (e.g.,sub-ns) which allows both time binning and time gating detection, an example of which is given in . Fig. 1C. As shown in Fig.1C, the time bins have both Raman and fluorescence signals whose relative amplitude changes over time, enabling the simultaneous measurement of both signals. Analysis of the early time bins (e.g., coinciding with the pulsed laser excitation) shows the Raman signal with the largest amplitude-to-background ratio, which is essentially a fluorescence ratio. At later time points (e.g., after the pulsed laser excitation), time bins have a negligible amount of or no Raman photons, and the detected signal is dominated by fluorescence, enabling time-resolved fluorescence spectroscopy. In some implementations, as described above, the controller 122 may be configured to coordinate operation of one or more elements of the optical system 100.Thus, in some implementations, controller 122 may coordinate operation of one or more elements of optical system 100, such as optical source 102 and detector array 118, to enable time-resolved measurement and temporal discrimination of Raman and fluorescence signals. In some implementations, optical system 100 may use time gating to reject signals outside a set detection window (e.g., when a SPAD is disabled).

[0055] Regarding point (2), increased sensitivity and measurement speed can be enabled by a high repetition rate laser in combination with the detector array 118 (e.g., a highly sensitive SPAD array) and time-binned / time-gated detection (which, for example, suppresses the fluorescence background and improves the SNR). Since the SNR scales with a square root of the number of detected photons (i.e., optical pulses), increasing a laser repetition rate increases the SNR for a constant measurement time (or, conversely, increases the measurement speed for a constant SNR). A higher SNR leads to greater sensitivity for detecting weak Raman signals that would otherwise be obscured by a background signal (e.g., a fluorescence signal).In some implementations, the optical system 100 may enable increased sensitivity and measurement speed by splitting the optical signal 160 into spatially separated spectral bands 165 that are imaged onto the detector array 118 in a 2D arrangement without significant power loss, as described herein.

[0056] With respect to point (3), at the same size as conventional solutions, the optical system 100 can achieve higher resolution and / or cover a larger spectral range. Alternatively, the optical system 100 described herein can achieve the same performance as the conventional solutions, but within a smaller footprint. This is made possible by the optical spectral banding design, which separates the optical signal, including the full spectral range, into spectral bands 165 and rearranges the spectral bands 165 to maximize the use of an active area of the detector array 118, as described herein (e.g., in combination with a capable 2D SPAD array detector). As described herein, the spectral bands 165 can be rearranged in various ways, e.g., depending on a spectral range objective and / or a spectral resolution objective.In general, the number of spectral bands 165 can be varied and a covered spectral range or a spectral range of each spectral band 165 can be set freely and independently of the other spectral bands 165 (e.g., to achieve a performance target).

[0057] With respect to point (4), a size improvement can be defined as a reduction in the footprint of the optical system (e.g., including collection optics and the spectrograph), which can be enabled by the optical spectral band design approach described here. As a result of the reduced footprint, sizes of optical and mechanical components can also be reduced, thereby reducing the overall weight of the spectroscopy engine. The latter can also lead to reduced power consumption, as it may take less time to temperature-adjust or maintain an optical system with a smaller footprint and / or lower weight. In some implementations, an optical design of the optical system 100 can serve to enable a reduction in the footprint or weight of the optical system 100.For example, the design of the optical system 100 may be configured such that one or more elements are used on both a detection beam path (e.g., a beam path of the optical signal 160) and an illumination beam path (e.g., a beam path of the excitation light 150), meaning that the detection beam path and the illumination beam path at least partially overlap. Such an optical design enables a smaller footprint by using the same physical space for a certain portion of multiple beam paths and may also enable reduced weight by using one or more of the same optical elements on the multiple beam paths. Other components of the system that contribute to improving SWAP (size, weight, and power) may include the laser source and the detector array.In some implementations, the laser source may be a highly integrated compact microchip device that delivers, for example, optical pulses at a specific wavelength (e.g., 532 nm) with a high repetition rate (e.g., at least about 500 kilohertz (kHz)), low energy (e.g., less than about 100 nanojoules (nJ)), and a narrow linewidth (e.g., less than about 0.1 nm). In some implementations, the detector array may be a highly sensitive 2D SPAD array with a pixel size and pixel count that provides a high (e.g., less than about 10 cm -1Wavenumber) spectral resolution. In some implementations, a pixel size and 2D array geometry can be selected to reduce the overall system footprint. When configured for operation in a visible wavelength range, SPAD detectors can be deployed with near-maximum efficiency and minimal noise, meaning that thermal cooling (e.g., compared to other Raman spectroscopy instruments) is required less frequently. Consequently, power consumption can be reduced.

[0058] Regarding point (5), sample damage can be reduced by using low-energy pulses, a detector array 118 in the form of a highly sensitive SPAD detector, and a beam scanning mechanism such as a MEMS scanner. Furthermore, by separating spectral bands 165 without loss of performance (apart from power losses caused by non-idealities of optical components), detection optimization in a given spectral band 165 is increased and SNR is increased, meaning that lower-power illumination can be used to illuminate the sample 155, thereby reducing the likelihood of damage to the sample 155.

[0059] With respect to item (6), a translation element may be integrated into the optical system 100 or into an external examination attachment and may be used to enable dynamic, spatially resolved Raman and fluorescence spectroscopy as described above.

[0060] As mentioned above, Fig. 1A-1C are provided as examples. Other examples may differ from what is described with reference to Fig. 1A-1C. Furthermore, the number and arrangement of the Fig. 1A-1B are provided as examples. In practice, additional elements, fewer elements, different elements, or differently arranged elements than those shown in Fig.1A-1B. For example, the physical design of the optical system 100 (e.g., a design of the optical source 102, the collection element 104, the filter 106, the optical device 110, or the like) provides the functionality described herein using free-space optics. Power and pulse energy of the optical source 102 may be relatively high, and the use of free-space optics is advantageous in terms of power consumption. Furthermore, free-space optics are efficient at collecting relatively weak reflected Raman signals. However, in some implementations, the physical design of the optical system 100 may be configured to provide the functionality described herein in other ways, such as using fiber- or waveguide-based optics (instead of or in addition to free-space optics).In some implementations, the selection of the technique used to provide the functionality of optical system 100 may be a design requirement for a given application, such as optical performance, size, power consumption, mechanical stability, or the like. Furthermore, two or more of the techniques described in . Fig. 1A-1B elements may be implemented within a single element or a single element in Fig. 1A-1B may be implemented as multiple distributed elements. Additionally or alternatively, a set of elements (e.g., one or more elements) included in Fig. 1A-1B, perform one or more functions that can be considered as performed by another set of elements shown in Fig. 1A-1B are described as fulfilled.

[0061] Fig.Figure 2, in combination with Table 1 (below), illustrates an example associated with the optical device 110 that enables flexible segmentation and arrangement of a full spectrum. Fig.2, the spectral bands 165 are arranged such that the spectral bands 165 are imaged in a stack in the band separation direction (e.g., a direction perpendicular to the dispersion direction) at the detector array 118. As noted above, the spectral bands 165 may be arranged in various ways, for example, depending on a spectral range, a spectral resolution, and / or a detection dynamic range and sensitivity objective. In some implementations, a number and areas of the spectral bands 165 may be varied, and each spectral range, resolution, dynamic range, and / or sensitivity of each spectral band 165 may be adjusted independently of those of the other spectral bands 165 (e.g., for the purpose of meeting specific performance objectives for a given application). For example, portions of the full spectrum that do not need to be measured or detected (e.g.,spectral band 165b), may be skipped (e.g., avoided or rejected) in some implementations. As another example, specific pixels or detector areas 120 of detector array 118 that cannot or should not be used may be avoided. Table 1 Spectrum band # Relative importance for sample identification Detector area # Band height (pixels) (size of the sensor) Spectral range (wavenumbers) Spectral bandwidth (wavenumbers) Spectral resolution (wavenumbers) 165a Normal 120a 200 400-700 300 1.5 165b Not monitored N / A N / A 700-1100 400 N / A 165c High 120b 400 1100-1600 500 0.5 165d Low 120c 100 0-400 400 4

[0062] Table 1 shows a numerical example illustrating attributes of the different spectral bands 165 mapped onto a 2D detector array 118 comprising three detector surfaces 120, as shown in Fig.1. In this example, a height of an example detector surface 120 is 700 pixels and an example spectral range (expressed as a spectral shift from the excitation wavelength) is 0 to 1600 wavenumbers. Here, a fraction of the full spectrum, spectral band 165b, is not measured or monitored and therefore not imaged onto the detector array 118, while the remainder of the full spectrum is divided into spectral band 165a, spectral band 165c, and spectral band 165d with different spectral ranges, resolutions, dynamic ranges, and sensitivities (e.g., scaling with the height on the detector array 118, referred to as band height in Table 1) and imaged onto different detector surfaces 120 of the detector array 118.

[0063] As mentioned above, Fig. 2 provided as an example. Other examples may differ from what is described with reference to Fig. 2 is described.

[0064] Fig. 3 and Fig. 4 are graphs associated with an increase in dynamic range and sensitivity enabled by optical device 110. In some implementations, dynamic range and sensitivity may be increased without changing the light collection and spectral separation at the front end. In one example implementation, a back-end imaging optic (e.g., one or more optical elements 116) may be configured to image energy in a spectral band 165 with a different, greater height onto detector array 118, at the expense of a reduced height or number of other spectral bands 165 for a fixed-size detector area. Alternatively, in another example implementation, two or more spectral bands 165 may be configured identically (e.g., spectral band 165a and spectral band 165d in Fig.3) and power in these spectral bands 165 can be distributed equally.

[0065] In the Fig. 3, the spectral band 165c has twice the height of the spectral band 165a (e.g., 200 pixels versus 100 pixels) on the detector array 118 (e.g., a height of the detector surface 120 at which the spectral band 165c is imaged is twice that of the detector surface 120 at which the spectral band 165a is imaged). If all spectral bands 165 have the same energy (e.g., power or throughput), then the spectral band 165c would have a pulse energy per pixel reduced by a factor of 2 compared to the spectral band 165a (and the spectral band 165d). The effect of reducing the energy density (e.g., energy per pixel) on the detector array 118 is illustrated in the Fig.4 for two channel sizes: a spectral channel with a specific width and height of 100 pixels and a spectral channel with a specific width and height of 200 pixels. As shown in Fig. 4, the higher channel (i.e., the spectral channel with a height of 200 pixels) has a larger dynamic range for count detection, resulting in increased sensitivity. In the Fig. 4, if the pulse energy were further increased, the detected counts per pulse would eventually saturate the detector array 118, meaning that the detector array 118 would not be able to detect more counts despite an increase in pulse energy. In some implementations, the sensitivity and saturation threshold can be increased by increasing the height (e.g., and the number of pixels) allocated to a particular spectral band 165.

[0066] In some implementations, a first spectral band 165x having a comparatively smaller bandwidth may be imaged on a first detector surface 110x of the detector array 118, and a second spectral band 165y having a comparatively larger bandwidth may be imaged on a second detector surface 110y of the detector array 118, while an overall width and pixel size (i.e., resolution) of the first detector surface 110x in the dispersion direction matches an overall width and pixel size (i.e., resolution) of the second detector surface 110y in the dispersion direction. In this way, if the optical resolution of a first spectral band 165x matches the optical resolution of a second spectral band 165y, the first spectral band 165x may be provided with a higher spectral resolution than the second spectral band 165y (e.g.,since each detector pixel receives fewer wavenumbers for the first spectral band 165x with the comparatively smaller bandwidth).

[0067] As mentioned above, Fig. 3 and Fig. 4 as examples. Other examples may differ from what is provided with reference to the Fig. 3 and Fig. 4 is described.

[0068] Fig.5-7 are diagrams illustrating example implementations of a separation element 112 described herein. In some implementations, as noted above, the separation element 112 may include one or more elements capable of spatially or angularly separating the optical signal 160 into a plurality of spectral bands 165 such that each spectral band 165 is spatially or angularly separated from other spectral bands 165. In some implementations, the separation element 112 may include a plurality of thin-film interference filters, each associated with a different spectral band 165 of the plurality of spectral bands 165. Fig. 5 is a diagram illustrating an example implementation of a separation element 112 comprising a plurality of (e.g., four) thin-film interference filters 502. Additionally or alternatively, these may comprise a diffraction grating. Fig. 6 and Fig.7 are diagrams illustrating an example implementation of a separation element 112 including a diffraction grating 602. Additionally or alternatively, the separation element 112 may include one or more other types of optical elements.

[0069] In some implementations, light of the optical signal 160 having a wavelength near a boundary between two spectral bands 165 may be split by the separation element 112 such that respective portions of the light enter a plurality of spectral bands 165. Thus, in some implementations, a spectral component at or near a boundary between a first spectral band 165 of the plurality of spectral bands 165 and a second spectral band 165 of the plurality of spectral bands 165 may be split such that a first portion of the spectral component is in the first spectral band 165 and a second portion of the spectral component is in the second spectral band 165. Here, the sum of the power of the first portion and the power of the second portion is a total power of the spectral component.

[0070] In the Fig.5, the optical signal 160 includes a full spectrum emanating from the sample 155 (e.g., as in Fig. 1B). Here, each thin-film interference filter 502 reflects only a fraction (e.g., a spectral band 165) of the full spectrum and transmits the rest. In some implementations, as in Fig. 5, a sequence of several (e.g., four) interference filters 502, followed by a mirror 504, divides the full spectrum into several (e.g., five) spatially separated spectral bands 165, which are then incident on a focusing lens 506 to convert the spatial separation (e.g., offset) into an angular separation (e.g., angle) of the different spectral bands 165. The spectral bands 165 can then be imaged onto a plane for further optical processing. In connection with the Fig.1B, the spatially / angularly separated spectral bands 165 are then directed onto the dispersive element 114.

[0071] In the Fig. 6 and Fig. 7, the optical signal 160 including the full spectrum emanating from the sample 155 (e.g. as in Fig. 2) collimated by a lens 604 and then directed onto a diffraction grating 602, which separates the incident light into different spectral components (e.g., wavelengths). The diffracted light emerging from the diffraction grating 602 is then focused and imaged by a lens 606 to produce spatially and angularly separated spectral bands 165. The Fig.7 includes a wedge 702 and prisms 704a and 704b, which are designed to change the beam path lengths and propagation angles of the rays of the spectral bands 165 in such a way that the emerging spectral rays appear to come from a single focal plane, but from different angles (e.g., analogous to the Fig. 5). In connection with the Fig. 1B, the spatially / angularly separated spectral bands 165 are then directed onto the dispersive element 114.

[0072] As mentioned above, Fig. 5-7 as examples. Other examples may differ from what is described with reference to Fig. 5-7. The number and arrangement of the Fig.The elements shown in Figures 5-7 are provided as examples. In practice, additional elements, fewer elements, different elements, or differently arranged elements than those shown in Fig. 5-7 shown. Furthermore, two or more in Fig. 5-7 elements can be implemented within a single element or a single element in Fig. 5-7 may be implemented as multiple distributed elements. Additionally or alternatively, a set of elements (e.g., one or more elements) contained in Fig. 5-7, perform one or more functions that can be considered as performed by another set of elements shown in Fig. 5-7 are described as fulfilled.

[0073] The above disclosure provides illustration and description, but is not intended to be exhaustive or to limit implementations to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be learned from practice of implementations. Furthermore, any of the implementations described herein may be combined unless the above disclosure expressly provides a reason why one or more implementations may not be combined.

[0074] Although certain combinations of features are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. Indeed, many of these features may be combined in ways not expressly recited in the claims and / or disclosed in the specification. Although each dependent claim recited below may depend directly on only one claim, the disclosure of various implementations includes each dependent claim in combination with every other claim in the claim set. As used herein, language referring to "at least one of" a list of items refers to any combination of those items, including individual members.For example, “at least one of: a, b or c” is intended to cover a, b, c, ab, ac, bc and abc and any combination with multiples of the same element.

[0075] When a component or one or more components (e.g., an optical element or one or more optical elements) is described or claimed (within a single claim or across multiple claims) to perform or be configured to perform multiple operations, that language is intended to broadly cover a variety of architectures and environments. For example, unless explicitly claimed otherwise (e.g.,by the use of "first component" and "second component" or by other language that distinguishes components in the claims), this language is intended to cover, for example, a single component that performs or is configured to perform all of the operations, a group of components that collectively perform all of the operations or are configured to perform all of the operations, a first component that performs or is configured to perform a first operation and a second component that performs or is configured to perform a second operation, or any combination of components that perform the operations or are configured to perform the operations.For example, if a claim takes the form "one or more components configured to perform X; perform Y; and perform Z", that claim should be interpreted to mean "one or more components configured to perform X; one or more (possibly different) components configured to perform Y; and one or more (also possibly different) components configured to perform Z".

[0076] No element, act, or instruction used herein should be construed as essential or essential unless expressly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more elements and may be used interchangeably with "one or more." Further, as used herein, the article "the" is intended to include one or more elements referred to in conjunction with the article "the" and may be used interchangeably with "the one or more." Further, as used herein, the term "set" is intended to include one or more elements (e.g., related elements, unrelated elements, or a combination of related and unrelated elements) and may be used interchangeably with "one or more."When only one element is meant, the phrase "merely a" or an analogous phrase is used. In addition, as used herein, the terms "comprises," "having," "having / comprising," or the like are open-ended terms. Further, the phrase "based on" is intended to mean "based at least in part on" unless expressly stated otherwise. In addition, as used herein, the term "or," when used in a sequence, is intended to be inclusive and may be used interchangeably with "and / or" unless expressly stated otherwise (e.g., when used in combination with "either" or "merely one of").Furthermore, for ease of description, spatially relative terms such as "beneath," "lower," "above," "upper," and the like may be used herein to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device, facility, and / or element in use or operation in addition to the orientation depicted in the figures. The device may be oriented differently (rotated 90 degrees or in other orientations), and the spatially relative terms used herein may also be interpreted accordingly.

[0077] Further aspects, features and embodiments of the present disclosure are described under the following points: 1. Optical system comprising: an optical source for providing excitation light; a collection element for: Directing an optical signal that is emitted by a sample as a reaction or Response to an incidence of the excitation light on the sample is received on an optical device; wherein the optical device comprises: a separating element for separating or splitting the optical signal into a plurality of spectral bands which are spatially or angularly separated along a band separation direction, wherein spectral ranges differ between each spectral band of the plurality of spectral bands, a dispersive element comprising a plurality of dispersive regions, wherein a dispersive region of the plurality of dispersive regions is configured to disperse spectral components of a spectral band of the plurality of spectral bands along a dispersion direction to form a dispersed spectral band, a plurality of optical elements, wherein one optical element of the plurality of optical elements is configured to manipulate the dispersed spectral band in association with or in connection with an imaging of the spectral band onto a detector surface or region of a detector array, and the detector array comprising the detector surface; and a controller for obtaining or receiving one or more readout signals from the detector array. 2. The optical system according to item 1, wherein the optical source is a pulsed laser source such that the excitation light comprises optical pulses with a high repetition rate, low energy, and narrow linewidth. 3. The optical system according to item 1 or 2, wherein the optical source is configured to reduce temporal jitter or temporal fluctuation in the excitation light or to perform synchronization to account for jitter or fluctuation in the excitation light. 4. An optical system according to any one of items 1 to 3, wherein the optical source is one of a plurality of optical sources each corresponding to at least one of: emitting at a different wavelength, generating excitation light with different pulse characteristics, or operating in a different operating mode. 5. The optical system according to any one of items 1 to 4, further comprising a scanning element for dithering or scanning the excitation light incident on the sample. 6. The optical system according to any one of items 1 to 5, wherein the one or more readout signals comprise a plurality of readout signals each obtainable or obtainable during a different acquisition window of a plurality of acquisition windows. 7. The optical system according to any one of item 6, wherein a time period of a first detection window of the plurality of detection windows is different from a time period of a second detection window of the plurality of detection windows. 8. The optical system of any one of items 1 to 7, wherein the one or more readout signals comprise a plurality of readout signals each obtainable simultaneously during a single acquisition window. 9. The optical system according to any one of items 1 to 8, wherein the controller is configured to perform synchronization to account for temporal jitter in the excitation light. 10. The optical system of any one of items 1 to 9, wherein the controller is configured to coordinate sampling of a readout signal of the one or more readout signals with excitation of the sample to enable time-resolved Raman spectroscopy. 11. The optical system of any one of items 1 to 10, wherein the controller is configured to time-align or time-sample a sampling of a readout signal of the one or more readout signals with an excitation of the sample to enable time-resolved fluorescence spectroscopy. 12. Optical system according to one of items 1 to 11, wherein the detector array is divided into a plurality of detector surfaces or regions, each of which is assigned to a different spectral band in the plurality of spectral bands or is linked to a different spectral band in the plurality of spectral bands. 13. The optical system according to any one of items 1 to 12, wherein the detector surface comprises a plurality of pixels in the dispersion direction and a plurality of pixels in the band separation direction. 14. Optical system according to one of items 1 to 13, wherein pixels of the detector surface are grouped into a plurality of macropixels. 15. The optical system according to any one of items 1 to 14, wherein the optical system is configured to synchronize a detection window associated with obtaining one or more readout signals with the excitation light and one or more other elements of the optical system associated with manipulating at least one of the excitation light, the optical signal, one or more of the plurality of spectral bands, or one or more of the plurality of optical elements. 16. The optical system of item 15, wherein the optical system is configured to synchronize the detection window and the one or more other elements in association with performing time-gated Raman spectroscopy, time-resolved fluorescence spectroscopy, dynamic spatially shifted real-time Raman spectroscopy (SORS), laser-induced breakdown spectroscopy (LIBS), or photoacoustic spectroscopy. 17. The optical system according to any one of items 1 to 16, further comprising a scanning interface mounted on a hermetic package that houses the optical device or that houses the optical device, the collection element and the optical source. 18. Optical system according to one of items 1 to 17, further comprising a displacement element for dynamically adjusting a spatial separation between an illumination beam path of the optical system and a detection beam path of the optical system. 19. The optical system of any one of items 1 to 18, further comprising a filter for removing one or more excitation wavelengths from the optical signal. 20. Optical system comprising: an optical source for providing excitation light; a collecting element for directing an optical signal received in response to the excitation light being incident on a sample to an optical device; wherein the optical device: the optical signal is designed to separate into a plurality of spectral bands which are spatially or angularly separated along a band separation direction, wherein each spectral band of the plurality of spectral bands has a different spectral range, Spectral components of a spectral band of the plurality of spectral bands are dispersed along a dispersion direction to form a dispersed spectral band, the dispersed spectral band is configured to be manipulated in association with or in connection with an imaging of the spectral band onto a detector surface or region of a detector array of the optical device; and a controller for receiving one or more readout signals from the detector array. 21. Optical system comprising: an optical source for providing excitation light; a collecting element for directing an optical signal received in response to the excitation light being incident on a sample to an optical device; wherein the optical device comprises: a separator for separating the optical signal into a plurality of spectral bands; wherein spectral ranges differ between each spectral band of the plurality of spectral bands; a dispersive element comprising a dispersive region, the dispersive region being configured to disperse spectral components of a spectral band of the plurality of spectral bands to form a dispersed spectral band; an optical element is configured to manipulate the dispersed spectral band in association with or in connection with an imaging of the spectral band onto a detector surface or region of a detector array, and the detector array comprises the detector area; and a controller for coordinating operation of the optical source with operation of the collection element or one or more elements of the optical device such that a time of reception of the optical signal is synchronized with a time of a detection window of the detector surface. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 620,080

[0001]

Claims

[1] Optical system comprising: an optical source for providing excitation light; a collection element for: Directing an optical signal received from a sample in response to the excitation light being incident on the sample to an optical device; wherein the optical device comprises: a separating element for separating the optical signal into a plurality of spectral bands which are spatially or angularly separated along a band separation direction, wherein spectral ranges differ between each spectral band of the plurality of spectral bands, a dispersive element comprising a plurality of dispersive regions, wherein a dispersive region of the plurality of dispersive regions is configured to disperse spectral components of a spectral band of the plurality of spectral bands along a dispersion direction to form a dispersed spectral band, a plurality of optical elements, wherein one optical element of the plurality of optical elements images the dispersed spectral band in association with or in connection with imaging the spectral band onto one or more optical elements. is designed to manipulate a detector surface or region of a detector array, and the detector array comprising the detector surface; and a controller for receiving one or more readout signals from the detector array. [2] The optical system of claim 1, wherein the optical source is a pulsed laser source such that the excitation light comprises optical pulses with a high repetition rate, a low energy and a narrow linewidth, and / or wherein the optical source is configured to reduce temporal jitter in the excitation light or to perform synchronization to account for jitter in the excitation light, and / or wherein the optical source is one of a plurality of optical sources each configured to do at least one of: emitting at a different wavelength, generating excitation light with different pulse characteristics, or operating in a different mode of operation. [3] The optical system according to claim 1 or 2, further comprising a scanning element for jittering or scanning the excitation light incident on the sample. [4] The optical system of any one of claims 1 to 3, wherein the one or more readout signals comprise a plurality of readout signals each obtainable during a different acquisition window of a plurality of acquisition windows, wherein optionally a time period of a first acquisition window of the plurality of acquisition windows differs from a time period of a second acquisition window of the plurality of acquisition windows. [5] An optical system according to any one of claims 1 to 4, wherein the one or more readout signals comprise a plurality of readout signals each obtainable or obtainable simultaneously during a single acquisition window. [6] The optical system of any one of claims 1 to 5, wherein the controller is configured to perform synchronization to account for temporal jitter in the excitation light, and / or wherein the controller is configured to coordinate sampling of a readout signal of the one or more readout signals with excitation of the sample to enable time-resolved Raman spectroscopy, and / or wherein the controller is configured to time-match or time-sample a readout signal of the one or more readout signals with excitation of the sample to enable time-resolved fluorescence spectroscopy. [7] An optical system according to any one of claims 1 to 6, wherein the detector array is divided into a plurality of detector areas or regions, each associated with a different spectral band in the plurality of spectral bands, and / or wherein the detector area comprises a plurality of pixels in the dispersion direction and a plurality of pixels in the band separation direction. [8] An optical system according to any one of claims 1 to 7, wherein pixels of the detector surface are grouped into a plurality of macropixels. [9] The optical system of any one of claims 1 to 8, wherein the optical system is configured to synchronize a detection window associated with obtaining one or more readout signals with the excitation light and one or more other elements of the optical system associated with manipulating at least one of the excitation light, the optical signal, one or more of the plurality of spectral bands, or one or more of the plurality of optical elements, optionally wherein the optical system is configured to synchronize the detection window and the one or more other elements in association with performing time-triggered or time-controlled synchronization.Time-gated Raman spectroscopy, time-resolved fluorescence spectroscopy, dynamic spatially shifted real-time Raman spectroscopy (SORS), laser-induced breakdown spectroscopy (LIBS), or photoacoustic spectroscopy. [10] An optical system according to any one of claims 1 to 9, further comprising a scanning interface mounted on a hermetic package that houses the optical device or that houses the optical device, the collection element and the optical source, and / or further comprising a displacement element for dynamically adjusting a spatial separation between an illumination optical path of the optical system and a detection optical path of the optical system. [11] An optical system according to any one of claims 1 to 10, further comprising a filter for removing one or more excitation wavelengths from the optical signal. [12] Optical system comprising: an optical source for providing excitation light; a collecting element for directing an optical signal received in response to the excitation light being incident on a sample to an optical device; wherein the optical device for: Separating the optical signal into a plurality of spectral bands that are spatially or angularly separated along a band separation direction, wherein each spectral band of the plurality of spectral bands has a different spectral range, Dispersing spectral components of a spectral band of the plurality of spectral bands along a dispersion direction to form a dispersed spectral band, Manipulating the dispersed spectral band in association with or in connection with imaging the spectral band onto a detector surface or region of a detector array of the optical device; and a controller for receiving one or more readout signals from the detector array. [13] Optical system comprising: an optical source for providing excitation light; a collecting element for directing an optical signal received in response to the excitation light being incident on a sample to an optical device; wherein the optical device comprises: a separator for separating the optical signal into a plurality of spectral bands; wherein spectral ranges differ between each spectral band of the plurality of spectral bands; a dispersive element comprising a dispersive region, the dispersive region being configured to disperse spectral components of a spectral band of the plurality of spectral bands to form a dispersed spectral band; an optical element is designed to manipulate the dispersed spectral band in association with or in connection with an imaging of the spectral band onto a detector surface or region of a detector array, and the detector array comprises the detector area; and a controller for coordinating operation of the optical source with operation of the collection element or one or more elements of the optical device such that a time of reception of the optical signal is synchronized with a time of a detection window of the detector surface.

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