Multispectral imaging system with deep ultraviolet oblique optical sectioning capability

Abstract

The application discloses a multispectral imaging system with deep ultraviolet oblique optical slicing capability, comprising a core lens assembly, a coaxial reflector and a guide ring-shaped illumination system; the core lens assembly comprises one or more lens elements; the coaxial reflector is located at the top of the core lens assembly and is arranged around the core lens assembly; the implementation scheme of the guide ring-shaped illumination system comprises a light source and a hollow reflecting surface, a ring-shaped light source and a ring-shaped light guide, the position of the light guide is adapted to the position of the core lens assembly, the position between the light source and the light guide is adapted, oblique illumination of the illumination light including deep ultraviolet is realized by adding the coaxial reflecting surface around the core lens for close-range focusing, and thus oblique illumination is realized, and the coaxial oblique illumination design overcomes the physical limitation of external off-axis light sources and is compatible with high-NA lenses.

Description

Technical Field

[0001] This invention relates to the field of microscopy, and more specifically to a multispectral imaging system with deep ultraviolet oblique optical sectioning capability. Background Technology

[0002] Multispectral imaging, covering the deep ultraviolet (UV), visible (VIS), and near-infrared (NIR) spectral regions, provides powerful analytical capabilities in numerous scientific and medical applications; deep ultraviolet microscopy has emerged as a promising technique that utilizes the shallow penetration depth of deep ultraviolet light combined with oblique illumination to achieve surface excitation; this method enables optical sectioning, which is invaluable for label-free imaging of non-sectioned tissue samples.

[0003] Traditional imaging systems face significant obstacles when using deep ultraviolet illumination, primarily due to the poor transmission characteristics of standard objective glass materials in the deep ultraviolet band. This technical limitation necessitates the use of dedicated and expensive deep ultraviolet transmission objectives, greatly increasing system cost and complexity. Furthermore, there are physical challenges in irradiating ultraviolet light onto angled samples, especially when using high-magnification objectives at short working distances. These combined limitations restrict the practical application of deep ultraviolet microscopy in laboratory and clinical settings. Summary of the Invention

[0004] The present invention proposes a multispectral imaging system with deep ultraviolet oblique optical slicing capability to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The multispectral imaging system of the present invention with deep ultraviolet oblique optical slicing capability includes a core lens assembly, a coaxial mirror, and a guiding ring illumination system; A multispectral imaging system with deep ultraviolet oblique optical slicing capability includes a core lens assembly, a coaxial mirror, and a guiding ring illumination system; The core lens assembly includes: one or more lens elements; The coaxial mirror is located on top of the core lens assembly and is arranged around the core lens assembly; The guiding ring lighting system includes a light source and a light guide capable of outputting ring lighting. The light guide is adapted to the position of the core lens assembly, the position of the light source and the light guide are adapted to each other, and the collecting optical element is located below the light guide.

[0006] Preferably, the light source is a collimated light source, the light guide is a hollow mirror, the hollow mirror is disposed below the core lens assembly, the collimated light source is disposed on the side of the hollow mirror, and the hollow mirror reflects the light generated by the collimated light source onto the reflecting surface of the coaxial mirror.

[0007] Preferably, the light source is a ring light source, the light guide is a ring light guide, the ring light guide is arranged around the core lens assembly, the ring light source is located below the ring light guide, and the ring light guide transmits the light emitted by the ring light source to the reflecting surface of the coaxial mirror through internal reflection.

[0008] Preferably, the coaxial mirror reflects several wavelengths of light transmitted by the optical guide and transmits them to the sample.

[0009] Preferably, the system further includes a collecting optical element located below the light guide.

[0010] Preferably, the illumination numerical aperture of the guiding ring lighting system is greater than or equal to the detection numerical aperture.

[0011] Preferably, the light source is provided with one or more, and the light source generates light in the deep ultraviolet, visible and near-infrared spectra.

[0012] Preferably, the system further includes a detector disposed on the side that collects the optical elements.

[0013] As can be seen from the above technical solution, the present invention provides a multispectral imaging system with deep ultraviolet oblique optical slicing capability. Compared with the prior art, the present invention has the following advantages: 1. This invention achieves oblique illumination by adding a coaxial reflective surface around the core lens for close-range focusing, thereby irradiating the sample with deep ultraviolet light, including deep ultraviolet light, at an oblique angle. The coaxial oblique illumination design overcomes the physical limitations of external off-axis light sources and is compatible with high-NA lenses.

[0014] 2. This invention uses a light beam to illuminate a hollow mirror to form a ring-shaped illumination pattern, or uses a light guide to transmit the ring-shaped light to the outside of the objective lens, so that the illumination wavelength and objective lens selection can be conveniently switched between software control and mechanical control.

[0015] 3. By placing the light source outside the objective lens, the objective lens volume is reduced, and the heat source is removed from its internal components, achieving simple thermal management through a simple heat sink. In addition, the ring illumination mode generated by the collimated beam of a single LED improves coupling efficiency without generating significant heat. To further enhance the illumination intensity, the external ring LED can be combined with the light guide to reduce light loss during propagation until it reaches the coaxial reflective surface.

[0016] 4. This invention supports transmitted bright field, up-irradiated fluorescence from near-outer to near-infrared and deep ultraviolet oblique illumination, thus broadening the diversity and application range. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the illumination mechanical structure integrated on the axis of the core lens according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the system configuration structure according to Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the illumination numerical aperture and detection numerical aperture of the multispectral imaging system with deep ultraviolet oblique optical slicing capability of the present invention. Figure 4 This is a schematic diagram of the system configuration structure of Embodiment 2 of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0019] like Figure 1 As shown, the multispectral imaging system with deep ultraviolet oblique optical slicing capability in this embodiment includes a core lens assembly, a coaxial mirror, and a guiding ring illumination system. The core lens assembly includes: one or more lens elements; The coaxial mirror is located on top of the core lens assembly and is arranged around the core lens assembly; The light source is a collimated light source, the light guide is a hollow mirror, the hollow mirror is located below the core lens assembly, the collimated light source is located on the side of the hollow mirror, and the hollow mirror reflects the light generated by the collimated light source onto the reflecting surface of the coaxial mirror.

[0020] like Figure 2 As shown, the system is an inverted microscope consisting of a dedicated NUV objective (i.e., the core lens assembly) with a coaxial oblique illumination sleeve, a collection optics element (e.g., a tubular lens), and a detector (e.g., CCD, CMOS, sCMOS, etc.). Multispectral and multicontrast imaging can be achieved by distributing the light source at different positions in the optical path: (1) The light source is positioned to guide the light through the sample toward the core lens group, thereby generating transmitted bright field contrast in the near-ultraviolet to near-infrared spectral range; (2) The light source is combined with a filter cube containing a dichroic spectrometer, an excitation filter and an emission filter to generate up-emitting fluorescence contrast in the near-ultraviolet to near-infrared spectral range. The positions of multiple filter cubes allow switching between different fluorescence channels or simultaneous excitation of multiple wavelengths; (3) The light source is guided to a hollow mirror system to form a ring illumination pattern, which is then reflected onto the sample by a coaxial mirror to achieve oblique illumination including deep ultraviolet wavelengths.

[0021] The system architecture also supports the simultaneous acquisition of multiple contrasts by distributing different light sources at different optical locations, thereby enabling the sequential or parallel collection of transmission, fluorescence, and oblique illumination data.

[0022] In practical applications, key performance indicators for evaluating the performance of lighting configurations include power measured at the image plane, coupling efficiency (expressed as the percentage of LED power reaching the image plane), and temperature near the LED printed circuit board. The illumination configuration of Example 1 achieves high coupling efficiency while maintaining a relatively low temperature of 27.7°C near the LED printed circuit board; this result demonstrates the superior efficiency of collimated beam transmission, in which a well-defined beam path results in minimal optical loss as it propagates to the sample.

[0023] A coaxial mirror reflects light of several wavelengths transmitted by a light guide and transmits it to a glass slide or sample.

[0024] Specifically, samples (such as thick tissue samples or optically extremely thin tissue sections) are placed on a glass or quartz surface, meaning the imaging plane is located on the far side of the glass. Standard glass slides or equipment commonly used in laboratories are 1 mm thick. However, lenses with higher NA (nanometer-field) are more prone to aberrations introduced by the glass or quartz without compensation. For example, differences in refractive index after passing through glass at different wavelengths can lead to axial chromatic aberration, lateral chromatic aberration, and field curvature, thus reducing image quality. The core lens of this invention includes an objective lens with 1.1 mm slide correction to overcome aberrations and optimize image quality from near-ultraviolet to near-infrared received wavelengths. Simultaneously, the coaxial illumination configuration adds deep ultraviolet optical slicing capabilities.

[0025] Furthermore, the numerical aperture of the guiding ring lighting system is greater than or equal to the numerical aperture of the detection; like Figure 3 As shown, the illumination numerical aperture configured in the system is greater than or equal to the detection numerical aperture. The design of this invention enables high-resolution multispectral imaging on a single integrated platform, with three different and complementary imaging contrasts: (1) deep ultraviolet oblique illumination to enhance surface contrast, (2) epi-fluorescence across near ultraviolet to near-infrared wavelengths, and (3) transmission bright-field imaging; this versatility greatly reduces the need for multiple specialized instruments and significantly expands the range of applications that the system can meet.

[0026] Furthermore, one or more light sources are provided, which produce light in the deep ultraviolet, near ultraviolet, visible and near infrared spectra.

[0027] Furthermore, the system also includes a detector, which is positioned on the side that collects the optical elements.

[0028] The system in this second embodiment is basically the same as the multispectral imaging system with deep ultraviolet oblique optical slicing capability in the first embodiment. The difference is that the light source is a ring light source, the light guide is a ring light guide, the ring light guide is arranged around the core lens assembly, the ring light source is located below the ring light guide, and the ring light guide transmits the light emitted by the ring light source to the reflective surface of the coaxial mirror through internal reflection.

[0029] like Figure 4 As shown, multispectral imaging can be performed using one or more ring LEDs of different wavelengths, or ring LEDs composed of different wavelengths. The light emitted by these ring LEDs is guided to the coaxial mirror through a deep ultraviolet-transmitting ring light guide. Importantly, the central optical axis remains unobstructed, allowing the detection light from the objective lens to pass through the center of the ring LED. This configuration provides excellent wavelength flexibility and simultaneously generates upper fluorescence contrast by adding an additional filter cube in the second optical layer.

[0030] The illumination configuration of Example 2 significantly improves power output and coupling efficiency; this configuration provides approximately 4 times the power to the image plane, which is higher than Example 1, and the coupling efficiency is approximately 1.6 times higher than that without a ring light guide. Despite the higher power, the temperature near the LED printed circuit board still exceeds 50°C, indicating that although the light guide improves optical efficiency by guiding diffused light through total internal reflection, additional thermal management strategies are still required for continuous operation.

[0031] Combining Embodiment 1 and Embodiment 2, the light source can consist of one or more light sources that output light at different wavelengths but share the same optical path. These light sources are electronically controlled by software, allowing users and researchers to select specific wavelengths for specific imaging applications without hardware modification or reconfiguration. This software-controlled wavelength selection significantly improves the system's flexibility and ease of use.

[0032] The shallow penetration depth of deep ultraviolet light enables effective optical sectioning by preferentially exciting fluorophores and generating label-free intrinsic contrast from the tissue surface; this surface-selective excitation significantly reduces scattered light from deep tissues, significantly improving the contrast and image clarity of thick, unsectioned tissue specimens.

[0033] In summary, this invention represents a significant advancement in deep ultraviolet microscopy and label-free tissue imaging by overcoming the fundamental limitations of traditional deep ultraviolet systems. Through innovative coaxial oblique illumination, flexible light guide and LED configurations, and integrated aberration correction, the system not only meets standard laboratory work and traditional sample preparation techniques but also achieves diverse imaging contrasts for various scientific and medical applications. Its modular architecture, thermal efficiency, and multi-contrast capabilities make this technology a powerful platform for advancing biomedical research, clinical diagnosis, and high-throughput tissue analysis.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0035] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multispectral imaging system with deep ultraviolet oblique optical slicing capability, characterized in that, It includes a core lens assembly, a coaxial mirror, and a guiding ring illumination system; The core lens assembly includes: one or more lens elements; The coaxial mirror is located on top of the core lens assembly and is arranged around the core lens assembly; The guiding ring lighting system includes a light source and a light guide capable of outputting ring lighting. The light guide is adapted to the position of the core lens assembly, the position of the light source and the light guide are adapted to each other, and the collecting optical element is located below the light guide.

2. The multispectral imaging system with deep ultraviolet oblique optical slicing capability according to claim 1, characterized in that, The light source is a collimated light source, the light guide is a hollow mirror, the hollow mirror is located below the core lens assembly, the collimated light source is located on the side of the hollow mirror, and the hollow mirror reflects the light generated by the collimated light source onto the reflecting surface of the coaxial mirror.

3. The multispectral imaging system with deep ultraviolet oblique optical slicing capability according to claim 1, characterized in that: The light source is a ring light source, and the light guide is a ring light guide. The ring light guide is arranged around the core lens assembly, and the ring light source is located below the ring light guide. The ring light guide transmits the light emitted by the ring light source to the reflecting surface of the coaxial mirror through internal reflection.

4. The multispectral imaging system with deep ultraviolet oblique optical slicing capability according to claim 1, characterized in that: The coaxial mirror reflects several wavelengths of light transmitted by the optical guide and transmits them to the sample.

5. The multispectral imaging system with deep ultraviolet oblique optical slicing capability according to claim 1, characterized in that: The system also includes a collection optical element located below the light guide.

6. The multispectral imaging system with deep ultraviolet oblique optical slicing capability according to claim 1, characterized in that: The illumination numerical aperture of the guiding ring lighting system is greater than or equal to the detection numerical aperture.

7. The multispectral imaging system with deep ultraviolet oblique optical slicing capability according to claim 1, characterized in that: The light source is provided in one or more, and the light source produces light in the deep ultraviolet, visible and near-infrared spectra.

8. The multispectral imaging system with deep ultraviolet oblique optical slicing capability according to claim 5, characterized in that: The system also includes a detector positioned on the side that collects the optical elements.

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