Spectrometry system with diffuser and filter array and isolated optical paths
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 to measure a sample, the spectrometer comprising:
a plurality of isolated optical paths extending from a filter array through a lens array to a sensor; and
a diffuser, the diffuser located between the sample and the filter array, the filter array located between the lens array and the diffuser, wherein the diffuser, filter array and the lens array are arranged to diffuse light from the sample incident on the filter array and the lens array.
2. The spectrometer of claim 1 , further comprising:
a plurality of regions of the sensor array;
a plurality of filters of the filter array;
a plurality of lenses of the lens array; and
a channel array extending between the plurality of regions of the sensor array and the plurality of lenses of the lens array, the channel array comprising a plurality of light transmitting channels defined with a material, wherein the plurality of isolated optical paths extends from the plurality of lenses through the plurality of channels to the plurality of regions in order to isolate the plurality of channels.
3. The spectrometer of claim 2 :
wherein each region of said plurality of regions comprises multiple sensors;
wherein each lens of the lens array corresponds to a region of said plurality of regions; and
wherein the filter array corresponds to the lens array, wherein each filter of the plurality of filters is configured to transmit a range of wavelengths different from other filters of the plurality.
4. A spectrometer as in claim 3 , wherein the plurality of filters comprises a plurality of interference filters, the plurality of interference filters arranged with the plurality of lenses in order to determine spectra of each of the plurality of regions.
5. A spectrometer as in claim 3 , further comprising a substrate having a thickness and a first side and a second side, the second side oriented toward the lens array and the sensor array, wherein a wavelength selective portion of the filter array is located on the second side oriented toward the lens array.
6. A spectrometer as in claim 5 , wherein the second side comprises a plurality of interference filters, said each of the plurality of interference filters on the second side configured to transmit a central wavelength of light to one lens of the plurality of lenses.
7. A spectrometer as in claim 5 , wherein the first side of the substrate does not comprise a coating.
8. The spectrometer of claim 3 wherein the plurality of filters comprises interference filters.
9. The spectrometer of claim 8 wherein the interference filters are deposited on a substrate thinner than 2 mm.
10. The spectrometer of claim 8 wherein the interference filters are deposited only on a single side of a substrate.
11. The spectrometer of claim 10 wherein the deposited side of the interference filters is facing towards the lens array.
12. A spectrometer as in claim 3 , wherein the lens array is positioned a focal length from the sensor array.
13. A spectrometer as in claim 3 , wherein the plurality of channels is dimensioned to define a clear lens aperture of each lens of the lens array, wherein the clear lens aperture of each lens is limited to one filter of the filter array.
14. A spectrometer as in claim 3 , further comprising a processor configured to determine spectra in response to signals from the detector.
15. A spectrometer as in claim 14 , wherein the processor comprises instructions to stitch together spectra from each of the regions in order to determine a spectrum of a target site of a material.
16. A spectrometer as in claim 3 , wherein the range of wavelengths overlaps with ranges of said other filters of the plurality.