Spectrometry systems with decreased light path
A spectrometer comprises a plurality of isolated optical channels comprising a plurality of isolated optical paths. The isolated optical paths decrease cross-talk among the optical paths and allow the spectrometer to have a decreased length with increased resolution. In many embodiments, the isolated optical paths comprise isolated parallel optical paths that allow the length of the device to be decreased substantially. In many embodiments, each isolated optical path extends from a filter of a filter array, through a lens of a lens array, through a channel of a support array, to a region of a sensor array. Each region of the sensor array comprises a plurality of sensor elements in which a location of the sensor element corresponds to the wavelength of light received based on an angle of light received at the location, the focal length of the lens and the central wavelength of the filter.
1. A spectrometer comprising:
a diffuser;
a detector comprising a plurality of regions, each region of said plurality of regions comprising multiple sensors;
a lens array comprising a plurality of lenses, each lens of the lens array corresponding to a region of said plurality of regions;
a filter array corresponding to the lens array, the filter array comprising a plurality of filters, wherein each filter of the plurality of filters is configured to transmit a range of wavelengths different from other filters of the plurality, wherein the diffuser comprises a cosine diffuser to generate a Lambertian light distribution; and
a support extending between the detector and the lens array, wherein the support is shaped and sized to support the lens array and position the lens array at a focal length from the detector, wherein the support comprises a plurality of channels configured to pass light from the plurality of lenses of the array to the plurality of regions of the detector.
2. The spectrometer of claim 1 , wherein the filter array comprises a substrate having a thickness and a first side and a second side, the first side oriented toward the diffuser, the second side oriented toward the lens array and the detector, wherein the filter array comprises a plurality of coatings on the second side to inhibit cross-talk among lenses of the array.
3. The spectrometer of claim 2 , wherein the plurality of coatings on the second side comprises a plurality of interference filters, wherein each of the plurality of interference filters are configured to transmit a central wavelength of light to a lens of the plurality of lenses.
4. The spectrometer of claim 2 , wherein the filter array comprises one or more coatings on the first side of the filter array.
5. The spectrometer of claim 4 , wherein the one or more coatings on the first side of the array comprise a coating configured to balance mechanical stress.
6. The spectrometer of claim 4 , wherein the one or more coatings on the first side of the filter array comprise an optical filter.
7. The spectrometer of claim 6 , wherein the optical filter on the first side of the filter array comprises an infrared pass filter configured to selectively pass infrared light.
8. The spectrometer of claim 2 , wherein the support comprises a light absorbing material located on a wall of each channel of the plurality of channels configured to inhibit cross-talk among the plurality of channels.
9. The spectrometer of claim 1 , wherein the support comprises an axis extending a distance from an upper surface of the detector to a lower surface of the lens array and wherein the support comprises stiffness in order to fix the distance from the upper surface to the lower surface at the focal length.
10. The spectrometer of claim 1 , wherein the image sensor comprises a bare die surface in contact with the support to position each of the plurality of lenses at the focal length from the bare die surface.
11. The spectrometer of claim 1 , wherein the plurality of regions comprises a plurality of active regions and wherein the plurality of channels corresponds to the plurality of active regions and wherein the support comprises end structures sized and shaped to contact the bare die surface at a plurality of contact locations away from the plurality of active regions.
12. The spectrometer of claim 1 , further comprising a filter support to hold the plurality of filters in place between the diffuser and the plurality of lenses.
13. The spectrometer of claim 1 , further comprising an optically transmissive plate placed over the plurality of filters configured to seal the plurality of filters.
14. The spectrometer of claim 1 , further comprising an infrared pass filter composed of an infrared transmissive material, wherein the diffuser is formed in a surface of the infrared transmissive material.
15. The spectrometer of claim 14 , further comprising a second diffuser formed in a second surface of the infrared transmissive material opposite the surface, wherein the second diffuser distributes incoming light across the diffuser.
16. The spectrometer of claim 15 , further comprising a second infrared pass filter and a housing, wherein the housing covering the diffuser, the filter array, and the lens array, wherein the housing is coupled to the second infrared pass filter and a support comprising a plurality of apertures and wherein the diffuser, the filter array, and the lens array are arranged sequentially between the second infrared pass filter and the support comprising the plurality of apertures in order to couple the support, the filter array and the lens array to a bare surface of the detector.
17. The spectrometer of claim 1 , further comprising: an illuminator, the illuminator comprising, a) a primary radiation emitter configured to emit primary radiation within a first wavelength range and, b) a secondary radiation emitter to emit secondary radiation within a second wavelength range different from the first wavelength range.
18. The spectrometer of claim 17 , wherein the secondary radiation emitter contacts packaging of the primary radiation emitter to inhibit heating of the secondary emitter and wherein the packaging comprises a heat sink configured to conduct heat away from the secondary radiation emitter.
19. The spectrometer of claim 17 , where a gap extends between the secondary radiation emitter and packaging of the primary radiation emitter configured to inhibit heating of the secondary emitter.
20. The spectrometer of claim 17 , further comprising a temperature sensor having a field of view configured to overlap with a field of view of the detector and a field of view of the illuminator.
21. The spectrometer of claim 17 , wherein the illuminator comprises optics configured to direct light from the secondary radiation emitter toward a field of view of the detector.