High-resolution out-of-focus compensation spectrometer

Abstract

Various embodiments of a high resolution spectrometer are disclosed herein. In one embodiment, a high resolution spectrometer includes a light source, a housing, at least one adjustment device secured to the housing, and an optical detector secured to the adjustment device. At least one dispersive optical element is positioned in optical communication with the light source and the optical detector, where the dispersive optical element is configured to diffract at least a portion of an incident optical signal from the light source into a diffracted optical signal propagating toward the optical detector, wherein the optical detector is configured to measure at least one characteristic of at least one wavelength component of the diffracted optical signal. The adjusting device is configured to change the position of the optical detector relative to the dispersive optical element so as to optimize the image width of the wavelength component of the diffracted optical signal.

Description

[0001] INTERACTION WITH RELATED APPLICATIONS

[0002] This application claims priority to U.S. Patent Application No. 18 / 119,018, filed March 8, 2023, entitled “High Resolution Defocus Compensation Spectrometer,” the contents of which are incorporated herein by reference. BACKGROUND

[0003] Spectroscopy is the study of the electromagnetic spectrum (wavelength composition of light) resulting from atomic and molecular interactions. Spectrometers and spectrophotometers have a wide range of applications in the physical, biological, and chemical fields. One of the design tradeoffs for these instruments is the need for compact size (i.e., smaller “design size”) versus optimizing the geometry of the instrument for high spectral resolution, which typically requires a larger design size.

[0004] While the prior art spectrometers have proven useful in the past, some shortcomings have been discovered. For example, because the diffraction angles for adjacent wavelengths can be very similar, spectrometers with high spectral resolution have a large distance between the image positions on the grating and the detector in order to obtain high spatial separation of adjacent wavelengths. However, this high separation of adjacent wavelengths typically requires a larger design size. In addition, typical spectrometer module designs use a planar detector and have only two wavelengths in the entire spectrum for which the focus is fully optimized, i.e., the image width is minimized. Thus, the entire spectrum is not fully optimized for focus and other wavelengths do not provide as high spectral resolution as possible. In view of the foregoing, there is a continuing need for a spectrometer that can provide high resolution and has a minimum design footprint. SUMMARY

[0005] Various embodiments of an optical instrument are disclosed. In one embodiment, the optical instrument includes at least one housing, at least one first adjustment device affixed to the at least one housing, at least one detector affixed to the at least one first adjustment device, and at least one dispersive optical element configured to receive light along an incident optical axis (A I) propagating an incident optical signal and diffracting at least a portion of the incident optical signal as a diffracted optical signal propagating toward at least one detector, wherein the at least one detector is configured to measure at least one characteristic of the diffracted optical signal, wherein the at least one first adjustment device is configured to change a position of the at least one detector relative to the at least one dispersive optical element. In various embodiments, the at least one first adjustment device is a linear motion stage having a fixed portion affixed to the housing and a movable portion affixed to the at least one detector, wherein the movable portion of the at least one first adjustment device is actuated by at least one actuator selected from the group consisting of a piezoelectric actuator, a servo motor actuator, a stepper motor actuator, and a linear motor actuator. The at least one first adjustment device is configured to change an angular orientation of the at least one detector relative to the at least one dispersive optical element, wherein the at least one first adjustment device is selected from the group consisting of an optical bench, a flip / tilt platform, a gimballed platform, a goniometer, an angular stage, and a flexure mount. In various embodiments, the at least one first adjustment device is actuated by at least one actuator selected from the group consisting of a piezoelectric actuator, a servo motor actuator, a stepper motor actuator, and a linear motor actuator. In other embodiments, the at least one dispersive optical element is affixed to at least one second adjustment device configured to change a position of the at least one dispersive optical element relative to at least one of the at least one detector or the incident optical signal. In other embodiments, the at least one dispersive optical element is affixed to at least one second adjustment device configured to change an angular orientation of the at least one dispersive optical element relative to at least one of the at least one detector or the incident optical signal. In one embodiment, the at least one dispersive optical element is a holographic grating having a groove profile selected from the group consisting of a sinusoidal profile, a trapezoidal profile, a convex profile, a cycloidal profile, an inverse cycloidal profile, a sawtooth profile, and an irregular quadrilateral sawtooth profile. In other embodiments, the at least one dispersive optical element is a diffractive grating selected from the group consisting of a blazed grating, a replicated grating, a double blazed grating, and a mosaic grating. In one embodiment, the at least one characteristic of the diffracted optical signal is an image width W of at least one wavelength component of the diffracted optical signal. The at least one characteristic of the diffracted optical signal can also be an optical power of at least one wavelength component of the diffracted optical signal.

[0006] Various embodiments of a method of analyzing an incident optical signal are also disclosed. In one embodiment, the method includes providing at least one dispersive optical element that operatively reflects the incident optical signal as a diffracted optical signal; providing at least one detector configured to measure one or more characteristics of the diffracted optical signal; providing at least one first adjustment device that operatively changes a position of the at least one detector relative to the at least one dispersive optical element; providing at least one controller configured to receive measurement data from the at least one detector indicative of the one or more characteristics of the diffracted optical signal and to command the at least one first adjustment device to position the at least one detector relative to the at least one dispersive optical element; subsequently measuring at least one of the one or more characteristics of the diffracted optical signal by using the at least one detector; and adjusting the position of the at least one detector relative to the at least one dispersive optical element using the at least one first adjustment device until an optimal value of the at least one of the one or more characteristics of the diffracted optical signal is achieved. The characteristics of the diffracted optical signal measured by the method include optical power of at least one first wavelength component λ1, at least one second wavelength component λ2, at least one third wavelength component λ3, at least one fourth wavelength component λ4, and at least one fifth wavelength component λ5.

[0007] In another embodiment, the method includes providing at least one dispersive optical element that operatively reflects an incident optical signal as a diffracted optical signal; providing at least one detector configured to measure one or more characteristics of the diffracted optical signal, wherein one of the one or more characteristics of the diffracted optical signal is an image width W n of at least one wavelength component λ n ; providing at least one first adjustment device that operatively changes a position of the at least one detector relative to the at least one dispersive optical element; providing at least one controller configured to receive measurement data from the at least one detector indicative of the image width W n of the first wavelength component λ1and to command the at least one first adjustment device to adjust the position of the at least one detector relative to the at least one dispersive optical element. The steps of the method include executing a control sequence that includes: in a first measurement step, measuring a first image width W1of the first wavelength component λ1using the at least one detector positioned at a first position P n relative to the at least one dispersive optical element; in a first movement step, positioning the at least one detector at a second position P n-1 relative to the at least one dispersive optical element using the at least one first adjustment device; in a second measurement step, measuring a second image width W2of the first wavelength component λ1using the at least one detector positioned at the second position P n-1a second image width W2 of the first wavelength component λ1 using at least one detector positioned at a second position P2 relative to the at least one dispersive optical element; comparing the first image width W1 to the second image width W2 in at least one controller to determine a first image width change ΔW1; if the first image width change ΔW1 is positive, positioning the at least one detector closer to the at least one dispersive optical element in a third movement step using the at least one first adjustment device by an incremental step size -ΔP1; and if the first image width change ΔW1 is negative, positioning the at least one detector closer to the at least one dispersive optical element in a second movement step using the at least one first adjustment device by the same incremental step size -ΔP1. The above control sequence steps are iterated as necessary until a minimum image width W min is achieved, which is then output to at least one display as data representing the minimum image width W min . The method further includes repeating the control sequence for a second wavelength component λ2, at least one third wavelength component λ3, at least one fourth wavelength component λ4, and at least one fifth wavelength component λ5 of the diffracted optical signal.

[0008] In another embodiment, a method includes providing at least one dispersive optical element that operatively diffracts an incident optical signal into a diffracted optical signal; providing at least one detector configured to measure one or more characteristics of the diffracted optical signal, wherein one of the one or more characteristics of the diffracted optical signal is an image width W n of one or more wavelength components λ n ; providing at least one first adjustment device that operatively changes a position of the at least one detector relative to the at least one dispersive optical element; providing at least one detector controller configured to receive measurement data from the at least one detector representing at least one characteristic of the diffracted optical signal; and providing at least one movement controller configured to command the at least one first adjustment device to adjust the position of the at least one detector relative to the at least one dispersive optical element. A control sequence is executed, wherein the control sequence includes: measuring a first image width W n of the first wavelength component λ1 in a first measurement step using the at least one detector positioned at a first position P n relative to the at least one dispersive optical element; transferring measurement data representing a second image width W n+1 from the at least one detector to the at least one detector controller and detector data representing the first position P n relative to the at least one dispersive optical element to the at least one movement controller; positioning the at least one detector closer to the at least one dispersive optical element in a first movement step using the at least one first adjustment device by a first incremental step size -ΔP nPositioned to a second position P relative to at least one dispersive optical element n-1 In the second measurement step, using at least one dispersive optical element positioned at a second position P n-1 At least one detector at a position to measure the second image width W of the first wavelength component λ1 n+1 In the second data acquisition step, the second image width W is represented n+1 The measurement data of the second position P relative to the at least one dispersive optical element are transmitted from the at least one detector to the at least one detector controller and are transmitted to the at least one detector controller. n-1 The detector position data is transmitted to at least one motion controller; in the second motion step, at least one first adjustment device is used to adjust at least one detector by a second incremental step length -ΔP n Positioned to a third position P relative to at least one dispersive optical element n-2 In the third measurement step, the at least one dispersive optical element is positioned at a third position (P n-2 ) to measure the third image width W of the first wavelength component λ1. n+2 In the third data acquisition step, the third image width W is represented n+2 The measurement data of the at least one detector is transmitted to the at least one detector controller, and a third position P representing the at least one detector relative to the at least one dispersive optical element is transmitted. n-2 The detector position data is transmitted to at least one motion controller; in the compiling step, the image width data and the detector position data from the sequential data acquisition step are compiled in at least one instrument controller, and the minimum image width W is selected from the compiled image width data. min Position at least one detector at the minimum image width W min The associated distance R min The method further comprises repeating the control sequence for the second wavelength component λ2, the at least one third wavelength component λ3, the at least one fourth wavelength component λ4 and the at least one fifth wavelength component λ5 of the diffractive optical signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various embodiments of the high-resolution spectrometer will be explained in more detail with reference to the accompanying drawings, in which:

[0010] Figure 1 and Figure 2 An optical schematic is shown showing the effect of different positions of the optical detector relative to the dispersive optical element.

[0011] Figure 3 and Figure 4 Display separately Figure 1 and Figure 2part of an optical schematic showing the separated wavelength components incident on the optical detector.

[0012] Figure 5 schematic showing an embodiment of a high resolution spectrometer with an optical detector at a first location for making measurements of a first wavelength component of the diffracted optical signal.

[0013] Figure 6 schematic showing an embodiment of a high resolution spectrometer with an optical detector at a second location for making measurements of a second wavelength component of the diffracted optical signal. Figure 5

[0014] Figures 7A to 7D schematic showing an embodiment of a high resolution spectrometer with an optical detector at a second location for making measurements of a second wavelength component of the diffracted optical signal. Figure 5 Figure 6 various views of the position change of the optical detector of the high resolution spectrometer shown.

[0015] Figure 8 image width plot of the three wavelength components measured by the embodiment of the spectrometer shown in Figure 5 Figure 6

[0016] Figure 9 image width plot of the three wavelength components measured by the embodiment of the high resolution spectrometer shown in Figure 5 Figure 6

[0017] Figure 10 plot of the image width of the high resolution spectrometer shown in Figure 5 Figure 6

[0018] Figure 11 control sequence diagram showing an embodiment of a method for optimizing spectrometer measurements.

[0019] Figure 12 control sequence diagram showing another embodiment of a method for optimizing spectrometer measurements. DETAILED DESCRIPTION

[0020] ​​​​​​​​Exemplary embodiments are described herein with reference to the accompanying drawings. Unless otherwise clear from the context, the size of elements, features, and components in the drawings and their relationship to each other in the drawings and the manner of these elements, features, and components are not necessarily drawn to scale, and can be exaggerated for clarity. In the drawings, like reference numerals designate like elements throughout the several views. As a result, even if the same or similar numerals are not mentioned or described in a corresponding drawing, they can be described with reference to other drawings. Also, elements not noted by element symbols can be described with reference to other drawings, even if they are not described.

[0021] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. Unless otherwise clear from the context, the singular forms "a," "an" and "the" used herein include plural forms as well. Also, the terms "at least one" and "one or more" can encompass both the singular and plural forms, according to the context. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise indicated herein, the terms such as "first," "second," and the like, merely describe a difference between one element and another, without necessarily limiting the elements. For example, one coupler can be referred to as a "first coupler," and similarly, another coupler can be referred to as a "second coupler," or vice versa.

[0022] Unless otherwise stated, spatially relative terms, such as "below," "beneath," "lower," "above," "upper," "upward," "downward," "vertical," "horizontal," and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The devices can be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. A set of reference axes (e.g., X, Y, Z), directions or coordinates, and rotations thereabout (e.g., θx, θy, θz) can be included in the figures for the purpose of guiding the reader's understanding of the figures and the specification, and are not necessarily intended to indicate any particular feature or element is aligned or in orthogonal with any other feature or element.

[0023] The paragraph numbers used herein are for organizational purposes only and should not be construed as limiting the subject matter recited. It is understood that there can be many different forms, embodiments and combinations of embodiments, and that the disclosure is directed to such, which can be practiced or carried out in various forms and implementations, and that the disclosure should not be construed as limited to the examples set forth herein. Rather, these examples and embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0024] The embodiments described below relate to spectrometers and spectrophotometers, both of which are used to separate and measure spectral components of a physical phenomenon. A spectrophotometer is a broad term that often is used to recite an instrument that measures a continuous variable of a phenomenon in which spectral components are mixed in some way. It works by using a dispersive device to split light into individual wavelengths and measuring the intensity of each wavelength with one or more optical sensors or detectors. A spectrometer is an instrument that separates light by wavelength and records this data. A spectrometer can often be an optical detector, a multi-channel optical detector, an optical detector array, an optical sensor, or a camera that detects and records a spectrum. Spectrophotometers and spectrometers differ in the way the results are measured and displayed. The resulting data is presented in the form of a graph that shows the intensity of light as a function of wavelength, which is called a spectrum. Operators of spectrophotometers and spectrometers often test samples to understand the behavior of these samples at a particular wavelength (also referred to herein as a "target wavelength") or multiple wavelengths (also referred to herein as "target wavelengths"). Similarly, a particular spectrum or sub-spectrum can also be referred to herein as a target "spectrum" or "sub-spectrum". Two important properties of a spectrometer are dispersion and angular resolution. Dispersion sets the wavelength range of the spectrum, and spectral resolution sets the size of the smallest spectral feature that can be investigated in the spectrum. When a grating is used as the dispersive device, the dispersion and spectral resolution are governed by the grating equation m l = d (sin a + sin b), which governs the angular position of the maximum intensity when light of wavelength l is diffracted from a grating with a groove spacing of d, where m is the diffraction order (an integer), a (alpha) is the angle of incidence, and b (beta) is the angle of diffraction, where both a and b are measured with respect to the grating normal. Angular dispersion is defined as the rate of change of the diffraction angle b with wavelength l. The spectral resolution (denoted as SR in this disclosure) of a spectrometer refers to the ability to distinguish between two wavelengths separated by a certain amount l, which can be expressed in nanometers or as a dimensionless quantity SR = l / l.

[0025] For clarity of disclosure, the following positional notation will be used. The position of a component, article, or feature is denoted by P n , an article at P n is considered to be at a position relative to another article, and in position P n-1An object that is closer to a second position (closer) relative to the same object or feature can be considered to be at a position that is -ΔP relative to the second position. For example, as described in the following paragraph, if a detector is at position P2 relative to a dispersive optical element (e.g., a grating), the same detector at position PI relative to the grating is closer to the grating. The notation is -ΔP n An incremental movement or step of ΔP relative to a position of a component, object, or feature indicates that the component, object, or feature is moved closer to each other by an amount (ΔP), and the notation is +ΔP n An incremental movement or step of -ΔP relative to a position of a component, object, or feature indicates that the component, object, or feature is moved farther from each other by the same amount (ΔP). It follows that if a detector is moved in the “+P direction” relative to a grating, the detector is moving away from the grating, and if the detector is moved in the “-P direction” relative to the grating, the detector is moving toward the grating.

[0026] The embodiments described below relate to improving the resolving power of a spectrometer or spectroscope by adjusting the position of an optical detector (or the position of a dispersive optical element) from a position of a sub-optimal focus of individual wavelength components of a diffracted optical signal (also referred to herein as “defocus”) to a position of an optimal focus of such wavelength components at the optical detector relative to the position of the dispersive optical element. The defocus of individual wavelength components can be caused by a variety of optical aberration effects (e.g., astigmatism, field curvature, etc., or combinations thereof). Aberration effects generally have different effects for different wavelengths, such that the position of the optimal focus relative to the dispersive optical element can be different for different wavelengths. The ability of a spectrometer to have the defocus effects corrected can be described as being “defocus-compensated” or having a “defocus compensation feature.” Such a defocus compensation feature can be turned on (i.e., “enabled”) or off (i.e., “disabled”) by an operator or by operation of a controller of the spectrometer.

[0027] Figure 1 and Figure 2 An optical schematic of a spectrometer 10 is shown, which is configured to measure a characteristic of an optical signal from a light source 12. In Figure 1 In the spectrometer 10, an optical signal 14 propagating from the light source 12 is incident on a dispersive optical element 16 (e.g., a diffraction grating 16) and diffracted as a diffracted optical signal 18 to a detector 20 at a position PI relative to the grating 16. The diffracted optical signal 18 shows individual rays having different wavelengths (also referred to herein as “wavelength components”) propagating at different angles β1, β2, β3, β4 at a first diffraction order. When adjacent wavelength components arrive at the detector 20, they are separated from each other by a wavelength change Δλ1. For example, the lower two wavelength components can have wavelengths λ1 (e.g., 450 nm) and λ2 (e.g., 480 nm), such that Δλ1 is 30 nanometers. The distance between the points of incidence of these two wavelength components on the detector plane is denoted as D1. In Figure 2In particular, the spectrometer 10 has the detector 20 positioned at a location P2 that is further from the grating 16 than the location PI. By having the detector 20 further from the grating 16, the wavelength components in the diffracted optical signal 18 that are separated by the same wavelength change Δλ1 are spatially separated at the relative points of incidence on the detector 20 by a greater distance D2.

[0028] Figure 3 and Figure 4 A detector 20 of the spectrometer 10 including a mask 22 having slits 24, 26, and 28 positioned in front of corresponding detector elements 25, 27, and 29, respectively, of the detector 20 is shown. Figure 3 A detector 20 of the spectrometer 10 including a mask 22 having slits 24, 26, and 28 positioned in front of corresponding detector elements 25, 27, and 29, respectively, of the detector 20 is shown. Figure 1 When the grating 16 is at the location PI shown, the wavelength separation Δλ1 results in a physical separation D1 that enables detection of a wavelength component λ1 (e.g., 450 nm) propagating through the slit 24 to the detector element 25 and a wavelength component λ2 (e.g., 480 nm) propagating through the slit 26 to the detector element 27. Figure 4 When the grating 16 is at the location PI shown, the wavelength separation Δλ1 results in a physical separation D1 that enables detection of a wavelength component λ1 (e.g., 450 nm) propagating through the slit 24 to the detector element 25 and a wavelength component λ2 (e.g., 480 nm) propagating through the slit 26 to the detector element 27. Figure 1 When the grating 16 is at the location PI shown, the wavelength separation Δλ1 results in a physical separation D1 that enables detection of a wavelength component λ1 (e.g., 450 nm) propagating through the slit 24 to the detector element 25 and a wavelength component λ2 (e.g., 480 nm) propagating through the slit 26 to the detector element 27.

[0029] Figure 5 and Figure 6 An optical schematic of an embodiment of an optical instrument 100 (e.g., a high-resolution spectrometer 100) configured to compensate for the defocusing effect of diffracted light in a first diffraction order for two wavelength components (λ1 and λ2), respectively, is shown. Figure 5 and Figure 6 Coordinate references are provided in the figures to show the X, Y, Z axes (or directions) and the Θχ, Θγ, and Θζ rotations about these axes. In general, the "Z direction" means movement along an optical axis (e.g., of a wavelength component of a diffracted optical signal, or in a direction optically upstream or downstream of the propagation direction of a wavelength component). In general, the "Y direction" means movement in a direction transverse to the Z direction (e.g., in a plane transverse to the optical axis of a wavelength component of a diffracted optical signal, or in a direction transverse to the propagation direction of a wavelength component). Figure 5 In particular, the Z axis is aligned with a particular optical axis A O1 (e.g., along which a wavelength component λ1 propagates). In various embodiments, the spectrometer 100 can have sufficient resolution to measure finely divided wavelength components λ1 = 450.00 nm, λ2 = 450.15 nm, λ3 = 450.45 nm, λ4 = 450.60 nm, etc.

[0030] As in Figure 5As shown in the illustrated embodiment, the spectrometer 100 includes at least one housing 102 having at least one internal volume 103, at least one entrance port 105 formed in the housing 102, at least one dispersive optical element 108 (also referred to herein as a "grating 108"), at least one optical sensor or detector 112, and at least one adjustment device 114, all of which are positioned on or secured to portions of the housing 102. The spectrometer 100 also includes an instrument controller 120 (also referred to herein as a "controller 120") having a detector controller 122 in electrical communication with the detector 112 via a conduit 118 and a motion controller 124 in electrical communication with the adjustment device 114 and an adjustment device 140 via conduits 116 and 142, respectively. At least one display 126 is in electrical communication with the instrument controller 120 to display the results of measurements by the spectrometer 100. In various embodiments, the detector 112 can include various slits configured to distinguish between wavelength components being measured. The slits can have a width ranging from 5 microns to 500 microns, although one skilled in the art will appreciate that the slits can be of any size.

[0031] The at least one light source 104 emits at least one incident optical signal 106 that propagates along an incident optical axis A I through the entrance port 105 to impinge on the grating 108 at an angle a (alpha) relative to a grating normal. The grating 108 diffracts the incident optical signal 106 into a diffracted optical signal 110 having one or more (or several) wavelength components, where each wavelength component λ n at an angle β relative to the grating normal. The angle β n propagates toward the detector 112, where the angle β n by a surface morphology (e.g., groove spacing or groove profile) of the grating 108. For example, a first wavelength component having a wavelength λ1is considered to be diffracted at a β1angle relative to the grating normal (e.g., based on the surface topography of the grating 108) and along a diffracted optical axis A O1 to the detector 112, which is shown as Figure 1 For simplicity, the light source 104 is shown as a point source that emits the incident optical signal 106. In various embodiments, the light source 104 can be any object that emits or reflects polychromatic light that can be analyzed by the spectrometer 100. For example, in one embodiment, the sample is a biological sample that is illuminated by a broad frequency light source (not shown) such that light reflected from the sample (e.g., the incident optical signal 106) propagates along the incident optical axis A IPropagates through the inlet end 105. In another embodiment, the light source 104 can be a light source that emits light at multiple wavelengths, such as an LED. In another embodiment, the light source 104 is an optical fiber that is in optical communication with the sample or the light source. The spectrometer 100 may include an aperture or entrance slit (not shown) mounted on the inlet end 105 that limits the amount of light or wavelength of light from the light source 104 that is allowed to propagate to the grating 108. In the illustrated embodiment, the housing 102 is pneumatically sealed, but with the exception of one or more filters configured to prevent particulate contaminants from entering the housing 102 into the interior volume 103. In other embodiments, the housing 102 is pneumatically sealed and a gas (e.g., an inert gas) is introduced into the interior volume 103. Those skilled in the art will appreciate that the housing can be configured in any manner to control the environment in the interior volume 103.

[0032] Although for Figure 5 and Figure 6 The embodiment of spectrometer 100 described herein measures wavelength components of the first diffraction order, but those skilled in the art will appreciate that spectrometer 100 can be used to measure wavelength components of higher or negative diffraction orders. Incident optical signal 106 is shown as a diverging beam to illustrate how dispersive optical element 108 (when configured as a concave grating) focuses each wavelength component of diffracted optical signal 110 (shown as a converging beam) relative to detector 112. In the illustrated embodiment, grating 108 is a concave holographic grating. Those skilled in the art will appreciate that grating 108 can be configured as any type of dispersive element, including diffraction gratings, such as ruled gratings, step gratings (single or multi-blazed), tiled gratings, holographic gratings, and replicas thereof. When configured as a holographic grating, the groove profile can be any type of profile, including a sinusoidal profile, a trapezoidal profile, a convex profile, a cycloidal profile, an inverted cycloidal profile, a sawtooth profile, or a trapezoidal sawtooth profile. The dispersive surface of the grating 108 can be planar, convex, concave, or any other shape or configuration. In some embodiments, the grating surface can be coated with a dielectric material (e.g., a metal oxide such as silicon dioxide (SiO2) or magnesium fluoride (MgF2), in a single layer, multiple alternating layers, or a combination thereof) to at least partially protect the grating surface in applications involving high laser energy density at the grating surface. The grating surface can also be coated with various metals (e.g., aluminum, gold, silver, etc.). Those skilled in the art will appreciate that the grating surface can be coated with any variety of materials. The dispersive optical element 108 can also be configured as a transmission grating, a prism, or a prism pair. In other embodiments, multiple dispersive elements can be used.

[0033] The detector 112 is configured to detect or measure one or more optical properties of the diffracted optical signal 110, or one or more optical properties of individual wavelength components of the diffracted optical signal 110, including but not limited to optical power, optical image width, optical image profile, beam profile, laser energy density, number of photons, wavelength, optical spectrum, sub-spectrum, multiple spectrum or sub-spectrum, etc. or any combination thereof, and to transmit measurement data representing such optical properties to the detector controller 122. In the illustrated embodiment, the detector 112 is provided as a wavelength-agnostic detector configured to measure optical power of wavelength components of the diffracted optical signal 110 focused thereon or allowed to propagate thereto. The detector 112 can include a plurality of detector elements (not shown), each of which is configured to measure at least one wavelength component of the diffracted optical signal 110. The detector 112 can also be provided as a detector array or a photon counter.

[0034] The spectrometer 100 can be configured to operate at various optical powers, wavelength ranges or multiple wavelength ranges, depending on the type of light source 104, dispersive optical element 108, detector 112 or adjustment device 114 used. Examples of wavelength ranges include ultraviolet (extreme ultraviolet, vacuum ultraviolet, deep ultraviolet), visible, near infrared, mid infrared and far infrared. The spectrometer 100 can also be reconfigured by replacing any of the above-mentioned components with other components configured to operate at different powers, wavelengths, etc.

[0035] Examples of sensor / detector types that can be incorporated into the spectrometer 100 include photodiodes (PDs), avalanche photodiodes (APDs), phototransistors, photodiode arrays, charge-coupled devices (CCDs), PIN diodes, CMOS sensors, and the like. In the illustrated embodiment, the detector 112 is a silicon (Si) detector having a response to wavelengths ranging from about 190 nanometers to about 1100 nanometers. Detector materials (and their ranges of proximity response) that can be used as the detector 112 include, but are not limited to, silicon (Si) VUV detectors (193 nm), Si RGB color sensors (blue 400-450 nm, green 470-600 nm, and red 590-720 nm), gallium nitride (GaN, 362-375 nm), gallium arsenide phosphide (GaAsP, 430-690 nm), germanium (Ge, 800-1800 nm), indium arsenide (InAs, 1000-3800 nm), indium gallium arsenide (InGaAs, 900-1700 nm), extended range InGaAs (900-2500 nm), gallium arsenide (GaAs, 900-1700 nm), lead sulfide (PbS, 1000-1300 nm), mercury cadmium telluride (HgCdTe, 2000-26000 nm) detectors. In addition to the detector types and materials listed above, there are many detector variants designed specifically for particular wavelengths or ranges of wavelengths. Those skilled in the art will appreciate that any of the wide variety of detectors having any of a variety of wavelength response ranges can be used. The detector 112 can be coated with various thin film or nano-textured coatings depending on the performance requirements at any of the wavelength ranges listed above.

[0036] In various embodiments, the adjustment device 114 is configured to change the orientation of the detector 112 relative to the grating 108 or the diffracted optical signal 110, i.e., in the X, Y, Z, Θχ, Θγ, or Θζdirections, rotations, or degrees of freedom. The adjustment device 114 can also compound the positioning of the detector 112 (e.g., change the orientation in both the X and Θχdegrees of freedom or in the X direction and the Z direction simultaneously). The center, pivot point, or pivot axis of the rotational degrees of freedom Θχ, Θγ, or Θζmay or can not overlap any surface of the detector 112. In one embodiment, the adjustment device 114 can change the orientation of the detector 112 by translating the detector 112 in the -P direction from a first position P n to a second position P n-1 (i.e., in the optically upstream direction) relative to the grating 108, or in the +P direction from the first position P n to the second position P n+1(i.e., in an optical downstream direction) away from the grating 108. The adjustment device 114 can be commanded by the detector controller 122 to move the detector 112 in position increments, such as increments -ΔΡ toward the grating 108, or increments +ΔΡ away from the grating 108. Because the different wavelength components propagate in somewhat different directions or along different optical axes, the Z axis or Z direction shown can not be aligned with all of the propagation directions of the wavelength components of the diffracted optical signal 110. Figure 5 and Figure 6 The Z axis or Z direction shown can not be aligned with all of the propagation directions of the wavelength components of the diffracted optical signal 110.

[0037] The adjustment device 114 is affixed to a structure of the housing 102, and the detector 112 is affixed to the adjustment device 114. In one embodiment, the adjustment device 114 is configured to change the position of the detector 112 relative to the grating 108 or relative to any of the wavelength components of the diffracted optical signal 110. When so configured, the adjustment device 114 can change the position of the detector 112 by positioning the detector 112 in an optical upstream direction (e.g., in the -P direction toward the grating 108) or in an optical downstream direction (e.g., in the +P direction away from the grating 108) along an optical axis of any of the wavelength components of the diffracted optical signal 110 at a given position P relative to the grating 108. n In addition, the adjustment device 114 can also change the position of the detector 112 laterally relative to the optical axis of any of the wavelength components of the diffracted optical signal 110. In the illustrated embodiment, the grating 108 is affixed to an adjustment device 140 that is configured to change the position or orientation of the grating 108 relative to at least one of the light source 104, the incident optical signal 106, or the detector 112. In another embodiment, the grating 108 is affixed to the housing 102 and is therefore not configured to move or adjust.

[0038] During operation of the optical spectrometer 100, the motion controller 124 is configured to send commands to the adjustment device 114 to change the position of the detector 112 in response to the commands, and / or to send commands to the adjustment device 140 to change the position of the grating 108 in response to the commands. For example, the adjustment device 114 can be commanded by the motion controller 124 to move the detector 112 in position increments, such as an increment -ΔΡ toward the grating 108 or an increment +ΔΡ away from the grating 108. The adjustment device 114 can be configured to communicate data representing the position (P) of the detector 112 relative to the grating 108 to the motion controller 124 as needed for control of the optical spectrometer 100. The controller 120 can include any of a variety of processors or computing modules configured to perform the functions of the optical spectrometer 100. Further, the structure and functions of the detector controller 122 and the motion controller 124 can be located elsewhere in the controller 120 and carried out there, or can be assigned to the adjustment device 114 and / or the adjustment device 140. Data from the detector 112, the adjustment device 114, the adjustment device 140 can be communicated to the controller 120, the detector controller 122, or the motion controller 124 wirelessly. In some embodiments, the optical spectrometer 100 can be implemented as an optical spectrometer module for integration into a variety of other instruments (e.g., a spectrometer). In some embodiments, the adjustment device 114 or the adjustment device 140 can be configured to adjust the position of the detector 112 or the grating 108 in response to temperature changes of components of the optical spectrometer 100 (e.g., to compensate for movement of components in the optical spectrometer 100 due to different coefficients of thermal expansion of the components).

[0039] While the grating 108 diffracts the incident optical signal 106 into a plurality of wavelength components, only one wavelength component (at a first target wavelength λ1) in the diffracted optical signal 110 is shown, which is along a first diffracted optical axis A1. Figure 5 Only one wavelength component (at a first target wavelength λ1) in the diffracted optical signal 110 is shown, which is along a first diffracted optical axis A1. O1The optical signal 110 propagates at a first diffraction angle β1 relative to the grating normal and is focused at a first point of incidence on a detector 112 (e.g., incident on a detector element (not shown)) when the grating is positioned at a position P2 relative to the grating 108. The diffracted optical signal 110 at λ1 is focused by the grating 108 into a first image having a first image width W1 at the surface of the detector 112. Although the grating 108 is shown as a concave grating that focuses each wavelength component at the detector 112 in this embodiment, the grating 108 may alternatively be configured as a planar grating, and a focusing element (such as a lens) may be placed between the planar gratings to focus each wavelength component at the detector 112. In some embodiments, to increase the physical separation of the wavelength components while minimizing the design footprint of the spectrometer 100 , the diffracted optical signal 110 may be routed to one or more mirror devices (plane mirrors, concave mirrors, or convex mirrors) configured to reflect the diffracted optical signal 110 from the grating 108 to the detector 112 .

[0040] Figure 6 The same incident optical signal 106 is shown propagating from the light source 104 to the grating 108. The grating 108 diffracts the incident optical signal 106 into a diffraction pattern along the second diffraction axis A. O2 The diffracted optical signal 110 (i.e., a wavelength component having a wavelength λ2) at a second target wavelength λ2 propagates at a second diffraction angle β2 relative to the grating normal and is focused at a second incident point (e.g., a detector element (not shown)) on a detector 112. For clarity, Figure 6 Only the second wavelength component λ2 of the diffraction optical signal 110 is displayed. The second wavelength component λ2 is focused at the plane of the detector 112 into a second image having a second image width W2. In this embodiment, due to various optical aberration effects (e.g., astigmatism, field curvature, and defocus), the position of the best focus of the second wavelength component λ2 (i.e., the position where the second image W2 is the smallest) is located closer to the grating 108 than the position of the best focus of the first wavelength component λ1 (at position P1). If the detector 112 is kept at Figure 5 If the second wavelength component λ2 is at position P2 as shown, the second wavelength component λ2 will not be properly focused (i.e., the second image will be out of focus and therefore larger). In order to minimize or compensate for the out-of-focus of the second wavelength component λ2 (and minimize the second image width W2), the adjustment device 114 changes the position of the detector 112 in incremental steps of ΔP relative to the grating 108 to position P1, at which the image width of the wavelength component λ2 is minimized. Because the wavelength component λ2 of the diffraction optical signal 110 is along the optical axis A, the wavelength component λ2 of the diffraction optical signal 110 is not properly focused (i.e., the second image will be out of focus and therefore larger). In order to minimize or compensate for the out-of-focus of the second wavelength component λ2 (and minimize the second image width W2), the adjustment device 114 changes the position of the detector 112 in incremental steps of ΔP relative to the grating 108 to position P1, at which the image width of the wavelength component λ2 is minimized. O2propagates at a larger angle β2, so the adjustment device 114 moves the detector 112 towards the grating 108 in the -P direction (optically upstream) and in a transverse manner with respect to the -P direction, so that the detector 112 will receive the wavelength component 12 along the optical axis A O2 The skilled person will appreciate that the adjustment device 114 can move the detector 112 in various directions to optimize the performance of the spectrometer 100.

[0041] Figures 7A to 7D A schematic view of the adjustment device 114 is shown, adjusting the position of the detector 112 in various directions, along or around various axes, or with different degrees of freedom, with respect to the grating 108 or the diffracted optical signal 110 of one or more wavelength components. Figure 7A The detector 112 is shown pivoted by the adjustment device 114 around a pivot point located at an edge of the detector 112. Figure 7B The detector 112 is shown pivoted by the adjustment device 114 around a pivot point located at a surface of the detector 112. Figure 7C and Figure 7D The detector 112 is shown in a first position and a second position, where the detector 112 has been moved along the optical axis A O and in a transverse manner with respect to the optical axis A O of the wavelength component being measured. The skilled person will appreciate that the adjustment device 114 can position the detector 112 in any of various ways for the desired performance of the spectrometer 100.

[0042] To change the position of the detector 112 with respect to the grating 108 (or to change the position of the grating 108 with respect to the detector 112), the adjustment device 114 (or adjustment device 140) can be provided as a motion stage having a fixed part and a movable part, where the grating 108 is fixed to the movable part, and the movable part is driven by an actuator. For the purposes of the present disclosure, the statement "the detector 112 is fixed to the adjustment device 114" means that the detector 112 is fixed to the movable part of the adjustment device 114, so that the position of the detector 112 can be changed by the adjustment device 114. Exemplary motion stages include, but are not limited to, linear stages, screw-driven linear stages, manual linear stages, vertical stages, vertical positioners, etc., or any combination thereof. These motion stages can be driven by various actuators, including but not limited to linear motors, servo motors, stepper motors, electrostrictive actuators, piezoelectric drivers, etc., or any combination thereof. The adjustment device 114 can move the detector in an open-loop manner or in a closed-loop manner (e.g., based on optical feedback, encoder feedback, or by counting the number of steps (in the case of a stepper motor)). Alternatively, the adjustment device 114 can be a linear stage driven manually (e.g., by a screw or micrometer) or other manual linear actuator.

[0043] In some embodiments, adjustment device 114 can be configured to change the angular orientation (e.g., pitch, roll, yaw, or a combination thereof) of detector 112 relative to grating 108. Similarly, adjustment device 140 can be configured to change the angular orientation (e.g., pitch, roll, yaw, or a combination thereof) of grating 108 relative to incident optical signal 106 or detector 112. When adjustment devices 114 and / or 140 are configured to change the angular orientation of detector 112 or grating 108, respectively, adjustment devices 114 and 140 can be configured as an optical mount, an optical rotation mount, a goniometric stage, a tilt / tilt platform, a rotation stage, a gimbaled optical mount, a hexapod robot, or any combination thereof. Each adjustment device can be driven by the actuators listed above for the linear adjustment device. In other embodiments, adjustment devices 114 and 140 can be configured as multiple kinematic stages or optical mounts connected to each other, so that the position and angular orientation of detector 112 and / or grating 108 can be adjusted simultaneously.

[0044] Figure 8 and Figure 9 The results show that for three example target wavelengths (or wavelength components) (λ1 = 380 nm, λ

[0045] Example image plane spot diagrams for an uncompensated spectrometer and a defocus-compensated spectrometer configuration with λ = 730 nm and λ = 1,080 nm. The spot diagrams show the size and shape of the image formed at a specific field and wavelength point (e.g., where each spot is the result of at least one ray of one of the target wavelengths falling on the detector). The area into which all spots are integrated becomes the image size W. In the illustrated embodiment of spectrometer 100, detector 112 uses a mask with slits oriented in the Y direction, so the image size in the X direction (i.e., "image width") is used to quantify the spectral resolution of spectrometer 100. The total width of the 10x10 grid of squares shown is 300 microns, with 10 divisions, so each square corresponds to 30 microns. Therefore, the term "image width" will be used to refer to the size of the image in the X direction. Those skilled in the art will appreciate that in alternative embodiments, the image size in the Y direction may be used.

[0046] Figure 8 Example image widths for wavelength components λ1, λ2, and λ3 of spectrometer 100 are shown when the defocus compensation feature is not used. Thus, for all three image width measurements, detector 112 can be positioned at first position P4. The image width (W1) for λ1 is approximately 150 microns, the image width (W1) for λ2 is approximately 240 microns, and the image width (W1) for λ3 is approximately 270 microns. Those skilled in the art will appreciate that any target wavelength can be selected for analysis by spectrometer 100.

[0047] Figure 9 The image width is shown for Figure 8 The example image widths for the wavelength components λΐ, λ2, and λ3 using the defocus-compensated spectrometer 100. For the image width measurement at λΐ, the detector 112 is moved (e.g., by adjustment device 114) to a position P3 closer to the grating 108. The resulting image width (W2) for λΐ is about 50 microns. For the image width measurement at λ2, the detector 112 is moved to a position P2 relative to the grating 108. The resulting image width (W2) for λ2 is about 85 microns. For the image width measurement at λ3, the detector 112 is moved to a position PI relative to the grating 108. The resulting image width (W2) for λ3 is about 80 microns. Those skilled in the art will appreciate that any target wavelength can be selected for analysis by the spectrometer 100.

[0048] Figure 10 A plot of image width (in microns) versus wavelength (in microns) is shown for an uncompensated spectrometer design (dashed line) versus a defocus-compensated spectrometer design (solid line), showing an improvement in image width by a factor of up to three. The degree of improvement in image width varies with wavelength for several reasons, including that optical aberrations and defocus effects can be wavelength-dependent. Those skilled in the art will appreciate that the defocus-compensated features of the spectrometer 100 can improve the image width by any degree, and the magnitude of the improvement can not vary in relation to or with wavelength.

[0049] Figure 11 An exemplary embodiment of steps of a method for measuring at least one characteristic of the diffracted optical signal 110 using the spectrometer 100 described above is shown. This embodiment includes a control sequence 200 that is operable to find a minimum image width of the diffracted optical signal 110 and the position of the minimum image width at multiple target wavelengths (also referred to herein as "selected wavelengths" or "wavelength components"). As described above, due to various optical aberration effects, the position of the best focus for different wavelength components of the diffracted optical signal 110 is located at different positions (e.g., optically upstream or downstream) along the propagation direction of the diffracted optical signal 110. The control sequence 200 is an iterative control loop configured to converge to the minimum image width by measuring the image width at various incremented positions of the detector 112 and monitoring the image width data to detect changes in the image width and reverse the movement of the detector 112 when the image width increases.

[0050] The control sequence 200 begins with a first measurement step 202 that measures a first image width Wl of a first wavelength component of the diffracted optical signal 110 having a wavelength λΐ using the optical detector 112 positioned at a first position P n The control sequence 200 begins with a first measurement step 202 that measures a first image width Wl of a first wavelength component of the diffracted optical signal 110 having a wavelength λΐ using the optical detector 112 positioned at a first position Pn The next step is a first movement step 204 which translates the optical detector 112 with an incremental step size -ΔP n to a second position P n-1 relative to the grating 108.

[0051] The next step is a second measurement step 206 which measures a second image width W n-1 of the first wavelength component of the diffracted optical signal 110 using the optical detector 112 positioned at the second position P n+1 relative to the grating 108. n+1 The next step is a perform calculation step 208 which is implemented in the controller 120 to calculate a first image width change (ΔW n ) by subtracting the first image width (W n ) from the second image width (W n ).

[0052] The calculation step 208 is followed by a logic step 210 which determines whether the first image width change (ΔW n ) is negative (where the image width decreases) or positive (where the image width increases). If the first image width change (ΔW n ) is negative (the image width becomes smaller), the next step is a second movement step 212 which translates the detector 112 with an incremental step size -ΔP n-2 to a third position P n relative to the grating 108. n If the first image width change (ΔW n-3 ) is positive (the image becomes larger), the next step is a third movement step 214 which translates the detector 112 with an incremental step size +ΔP n / 2 (in a direction away from the grating 108) to a fourth position P n-3 relative to the grating 108. In this third movement step 214, the incremental step size ΔP is halved as the control sequence progresses to converge on the minimum image width.

[0053] Following the third movement step 214, the measurement step 206, the calculation step 208, the logic step 210 and the movement step 212 (or the movement step 214) are repeated until the control sequence 200 converges on a minimum value of the image width W which is then communicated to the controller 120. Those skilled in the art will appreciate that the calculation and / or logic steps can be implemented in the controller 122, 124 or can be implemented on the detector 112 or the adjustment device 114.

[0054] The control sequence 200 as described above is an embodiment in which the detector 112 undergoes linear movement (towards or away from the grating 108 or laterally to both of the grating 108). In other embodiments, the control sequence 200 can be performed with angular orientation changes (e.g., as shown in Figure 7A and Figure 7B ) of the detector 112. In another embodiment, the control sequence 200 as described above can be performed by changing the position or angular orientation of the grating 108 relative to the detector 112.

[0055] Figure 12 The steps of an embodiment of the control sequence 300 for finding the minimum image width of the diffracted optical signal 110 and the location of the minimum image width at multiple target wavelengths (also referred to herein as "selected wavelengths" or "wavelength components") are shown. This embodiment of the control sequence 300 operationally translates (i.e., scans) the detector 112 (towards or away from the grating 108 or laterally to both of the grating 108) while capturing or recording data representing the image width at each of multiple positions relative to the grating 108 and sending this data to the controller 120 for processing and analysis. In one embodiment, after the scan, the controller 120 selects the minimum image width data, moves the detector 112 to this position and records the image width data. The control sequence 300 is then repeated for all desired wavelengths or wavelength components.

[0056] The control sequence 300 begins with a first measurement step 302 that measures a first image width W n of the diffracted optical signal 110 at a wavelength component λ1 (e.g., 450.00 nanometers) using the optical detector 112 positioned at a first position P n relative to the grating 108. A data retrieval step 304 is then performed in which the detector 112 transmits measurement data representing the first image width W n to the controller 120 and the adjustment device 114 transmits measurement data representing the first position P n to the motion controller 124. The next step is a first motion step 306 in which the adjustment device 114 moves the detector 112 in incremental steps -ΔP n to a second position P n-1 relative to the grating 108. The absolute value of the incremental step |ΔP n | can be selected based on desired or advantageous conditions.

[0057] The next step is a second measurement step 308 that measures a second image width W n-1 of the wavelength component λ1 using the optical detector 112 positioned at the second position P n+1Then, the data acquisition step 310 is performed, wherein the detector 112 represents the second image width W n+1 The measurement data of the second position P is transmitted to the controller 120, and the adjustment device 114 adjusts the second position P n-1 The measurement data is transmitted to the motion controller 124. The next step is a second motion step 312, in which the adjustment device 114 adjusts the detector 112 by an incremental step size of -ΔP n Move to the third position P relative to the grating 108 n-2 .

[0058] The next step is a third measurement step 314, which utilizes the optical detector 112 positioned at a third position P n-2 The optical detector 112 is used to measure the third image width W of the wavelength component λ1. n+2 Next, a third data acquisition step 316 is performed, wherein the detector 112 represents the third image width W n+2 The measurement data of is transmitted to the controller 120, and the adjustment device 114 will represent the third position P n-2 The measurement data is transmitted to the motion controller 124.

[0059] Although the process outlined above describes three measurement steps and two motion steps, this process may involve a large number of measurement steps and motion steps in order to collect sufficient data for processing to achieve a guaranteed minimum image width position. To do so, an iteration of step 318 is performed to repeat the measurement and motion steps to collect additional data.

[0060] When each data acquisition step 304, 310, 316 is performed, a compilation step 320 is performed in the instrument controller 120, which saves the sequential position data P n and its associated sequential image width data W n For later processing. For example, to position the detector 112 at a point relative to the grating 108 where the image width of the wavelength component λ1 is at a minimum, image width data is created for each movement increment performed by the adjustment device 114. After all the data has been compiled, the controller 120 can process this data to find the position of the detector 112 where the image width is minimum, then command the adjustment device 114 to move the detector 112 to this position in a third movement step 322 and perform a final measurement step 324 (e.g., of optical power or other performance parameter as selected by an operator or controller).

[0061] The above steps 302-324 are used to make a measurement of a selected wavelength λ1or wavelength component λ1(e.g., 450.00 nanometers) of the diffracted optical signal 110. The control sequence 300 can then be repeated (e.g., at the direction of the controller 120 or a system operator operating the spectrometer 100) as step 326 for another wavelength component λ2(e.g., 450.15 nanometers) and so on for a sufficient number of wavelength components to characterize the incident optical signal 106 to a desired degree of refinement. The end result can be a display of optical intensity as a function of wavelength (i.e., a spectral plot or spectrum of optical power over a target spectrum).

[0062] The above-described embodiments illustrate a spectrometer having the ability to vary the position of its detector to achieve optical results over a range of wavelengths. Those skilled in the art will appreciate that the above-described spectrometer configurations can be extended to achieve various other performance advantages without departing from the spirit of the foregoing description.

[0063] The foregoing is illustrative of embodiments and examples of the present application and is not intended to be limiting. Although specific embodiments and examples have been described herein, one skilled in the art will readily appreciate that many modifications are possible in the spirit of the novel teachings and advantages described herein. Accordingly, all such modifications are intended to be included within the scope of the present application as defined in the following claims in which the For example, those skilled in the art will appreciate that the patentable subject matter of any sentence, paragraph, example or embodiment can be combined with the patentable subject matter of some or all of the patentable subject matter of other sentences, paragraphs, examples or embodiments unless such combinations are mutually inconsistent. Accordingly, the scope of the present application should be determined by the following claims and equivalents thereof.

Claims

1. An optical instrument comprising: at least one housing; at least one first adjustment device secured to the at least one housing; at least one detector fixedly connected to the at least one first adjustment device; as well as At least one dispersive optical element configured to receive light along the incident optical axis (A I ), and diffracting at least a portion of the incident optical signal into a diffracted optical signal that propagates toward the at least one detector, wherein the at least one detector is configured to measure at least one characteristic of the diffracted optical signal, The at least one first adjustment device is configured to change a position of the at least one detector relative to the at least one dispersive optical element.

2. The optical instrument according to claim 1, wherein the at least one first adjustment device is a linear motion stage having a fixed portion fixed to the housing and a movable portion fixed to the at least one detector, wherein the movable portion of the at least one first adjustment device is actuated by at least one actuator, the at least one actuator being selected from the group consisting of a piezoelectric actuator, a servo motor actuator, a stepper motor actuator, and a linear motor actuator.

3. The optical instrument of claim 1 , wherein the at least one first adjustment device is configured to change an angular orientation of the at least one detector relative to the at least one dispersive optical element.

4. The optical instrument according to claim 3, wherein the at least one first adjustment device is selected from the group consisting of an optical bracket, a tilt / tilt platform, a universal platform, a goniometer, an angle stage, and a flexible bracket.

5. The optical instrument according to claim 4, wherein the at least one first adjustment device is actuated by at least one actuator, the at least one actuator being selected from the group consisting of a piezoelectric actuator, a servo motor actuator, a stepper motor actuator, and a linear motor actuator.

6. The optical instrument of claim 1 , wherein the at least one dispersive optical element is affixed to at least one second adjustment device, the at least one second adjustment device being configured to change a position of the at least one dispersive optical element relative to at least one of the at least one detector or the incident optical signal.

7. The optical instrument of claim 1 , wherein the at least one dispersive optical element is secured to at least one second adjustment device configured to change an angular orientation of the at least one dispersive optical element relative to at least one of the at least one detector or the incident optical signal.

8. The optical instrument of claim 1, wherein the at least one dispersive optical element is a holographic grating.

9. The optical instrument according to claim 8, wherein the holographic grating has a groove profile, and the groove profile is selected from the group consisting of a sinusoidal profile, a trapezoidal profile, a convex profile, a cycloid profile, an inverted cycloid profile, a sawtooth profile and an irregular trapezoidal sawtooth profile.

10. The optical instrument of claim 1, wherein the at least one dispersive optical element is a diffraction grating selected from the group consisting of an echelon grating, a replica grating, a double blazed grating, and a mosaic grating.

11. The optical instrument according to claim 1, wherein the at least one characteristic of the diffraction optical signal is an image width (W) of at least one wavelength component of the diffraction optical signal.

12. The optical instrument of claim 1, wherein the at least one characteristic of the diffracted optical signal is wavelength.

13. The optical instrument according to claim 1, wherein the at least one characteristic of the diffraction optical signal is an optical power of at least one wavelength component of the diffraction optical signal.

14. A method for analyzing an incident optical signal, comprising: providing at least one dispersive optical element, the at least one dispersive optical element being operative to reflect the incident optical signal as a diffracted optical signal; providing at least one detector configured to measure one or more characteristics of the diffractive optical signal; providing at least one first adjustment device operable to change a position of the at least one detector relative to the at least one dispersive optical element; providing at least one controller configured to receive measurement data representative of the one or more characteristics of the diffractive optical signal from the at least one detector and to command the at least one first adjustment device to position the at least one detector relative to the at least one dispersive optical element; measuring at least one of the one or more characteristics of the diffractive optical signal using the at least one detector; as well as The position of the at least one detector relative to the at least one dispersive optical element is adjusted using the at least one first adjustment device until an optimal value of the at least one characteristic among the one or more characteristics of the diffractive optical signal is achieved.

15. The method of claim 14, wherein one of the one or more characteristics of the diffracted optical signal is the optical power of at least one first wavelength component (λ1).

16. The method of claim 14, wherein one of the one or more characteristics of the diffracted optical signal is the optical power of at least one second wavelength component (λ2).

17. The method of claim 14, wherein one of the one or more characteristics of the diffracted optical signal is the optical power of at least one third wavelength component (λ3).

18. The method of claim 14, wherein one of the one or more characteristics of the diffracted optical signal is the optical power of at least one fourth wavelength component (λ4).

19. The method of claim 14, wherein one of the one or more characteristics of the diffracted optical signal is an optical power of at least one fifth wavelength component (λ5).

20. A method for analyzing an incident optical signal, comprising: providing at least one dispersive optical element, the at least one dispersive optical element being operative to reflect an incident optical signal as a diffracted optical signal; At least one detector is provided, the at least one detector being configured to measure one or more characteristics of the diffractive optical signal, wherein one of the one or more characteristics of the diffractive optical signal is one or more wavelength components (λ n ) image width (W n ); providing at least one first adjustment device operable to change a position of the at least one detector relative to the at least one dispersive optical element; At least one controller is provided, the at least one controller being configured to receive the image width (W) representing the first wavelength component (λ1) from the at least one detector. n ), and instructing the at least one first adjustment device to adjust the position of the at least one detector relative to the at least one dispersive optical element; Execute control sequences, including: In a first measurement step, the at least one dispersive optical element is positioned at a first position (P n ) to measure a first image width (W1) of the first wavelength component (λ1); In a first movement step, the at least one detector is positioned at a second position (P) relative to the at least one dispersive optical element using the at least one first adjustment device. n-1 ) In a second measurement step, the at least one dispersive optical element is positioned at the second position (P n-1 ) to measure a second image width (W2) of the first wavelength component (λ1); In the comparing step, the first image width (W1) is compared with the second image width (W2) in the at least one controller to determine a first image width change (ΔW1); If the first image width variation (ΔW1) is positive, in a third movement step, the at least one detector is positioned closer to the at least one dispersive optical element by an incremental step (-ΔP1) using the at least one first adjustment device; and If the first image width change (ΔW1) is negative, in a second movement step, positioning the at least one detector closer to the at least one dispersive optical element by the at least one first adjustment device with the same incremental step size (-ΔP1); The control sequence is repeated until the minimum image width (W min );as well as The minimum image width (W min ) data is output to at least one display.

21. The method of claim 20, further comprising repeating the control sequence for a second wavelength component (λ2) of the diffractive optical signal.

22. The method of claim 20, further comprising repeating the control sequence for a third wavelength component (λ3) of the diffractive optical signal.

23. The method of claim 20, further comprising repeating the control sequence for a fourth wavelength component (λ4) of the diffractive optical signal.

24. The method of claim 20, further comprising repeating the control sequence for a fifth wavelength component (λ5) of the diffractive optical signal.

25. The method of claim 20, further comprising repeating the control sequence for a sixth wavelength component (λ6) of the diffractive optical signal.

26. A method for analyzing an incident optical signal, comprising: providing at least one dispersive optical element, the at least one dispersive optical element being operative to diffract an incident optical signal into a diffracted optical signal; At least one detector is provided, the at least one detector being configured to measure one or more characteristics of the diffractive optical signal, wherein one of the one or more characteristics of the diffractive optical signal is one or more wavelength components (λ n ) image width (W n ); providing at least one first adjustment device operable to change a position of the at least one detector relative to the at least one dispersive optical element; providing at least one detector controller configured to receive measurement data representative of at least one characteristic of the diffractive optical signal from the at least one detector; providing at least one motion controller configured to command the at least one first adjustment device to adjust the position of the at least one detector relative to the at least one dispersive optical element; Execute control sequences, including: In a first measurement step, the at least one dispersive optical element is positioned at a first position (P n ) to measure the first image width (W n ); In the first data acquisition step, the second image width (W n+1 ) is transmitted from the at least one detector to the at least one detector controller, and the measurement data representing the first position (P) relative to the at least one dispersive optical element is transmitted to the at least one detector controller. n ) to the at least one motion controller; In the first movement step, the at least one detector is adjusted by the at least one first adjustment device by a first incremental step (-ΔP n ) is positioned to a second position (P) relative to the at least one dispersive optical element n-1 ); In a second measurement step, the at least one dispersive optical element is positioned at the second position (P n-1 ) to measure the second image width (W n+1 ); In the second data acquisition step, the second image width (W n+1 ) is transmitted from the at least one detector to the at least one detector controller, and the measurement data representing the second position (P) relative to the at least one dispersive optical element is transmitted to the at least one detector controller. n-1 ) to the at least one motion controller; In the second movement step, the at least one detector is adjusted by the at least one first adjustment device by a second incremental step (-ΔP n ) is positioned to a third position (P) relative to the at least one dispersive optical element n-2 ); In a third measurement step, the at least one dispersive optical element is positioned at the third position (P n-2 ) to measure the third image width (W n+2 ); In the third data acquisition step, the third image width (W n+2 ) is transmitted from the at least one detector to the at least one detector controller, and the third position (P) representing the at least one detector relative to the at least one dispersive optical element is transmitted to the at least one detector controller. n-2 ) to the at least one motion controller; In the compiling step, the image width data and the detector position data from the sequence data acquisition step are compiled in at least one instrument controller, and a minimum image width (W) is selected from the compiled image width data. min ); Positioning the at least one detector at a position corresponding to the minimum image width (W min ) associated distance (R min ) place.

27. The method of claim 26, further comprising repeating the control sequence for a second wavelength component (λ2) of the diffractive optical signal.

28. The method of claim 26, further comprising repeating the control sequence for a third wavelength component (λ3) of the diffractive optical signal.

29. The method of claim 26, further comprising repeating the control sequence for a fourth wavelength component (λ4) of the diffractive optical signal.

30. The method of claim 26, further comprising repeating the control sequence for a fifth wavelength component (λ5) of the diffractive optical signal.

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