Abstract: A method and apparatus for field spectroscopic characterization of seafood is disclosed. A portable NIR spectrometer is connected to an analyzer configured for performing a multivariate analysis of reflection spectra to determine qualitatively the true identities or quantitatively the freshness of seafood samples.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A method and apparatus for field spectroscopic characterization of seafood is disclosed. A portable NIR spectrometer is connected to an analyzer configured for performing a multivariate analysis of reflection spectra to determine qualitatively the true identities or quantitatively the freshness of seafood samples.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A method and apparatus for field spectroscopic characterization of seafood is disclosed. A portable NIR spectrometer is connected to an analyzer configured for performing a multivariate analysis of reflection spectra to determine qualitatively the true identities or quantitatively the freshness of seafood samples.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A portable spectrometer device includes an illumination source for directing at a sample, and a tapered light pipe (TLP) for capturing light interacting with the sample at a first focal ratio and for delivering the light at a second focal ratio lower than the first focal ratio. A linearly variable filter (LVF) separates the captured light into a spectrum of constituent wavelength signals; and a detector array, including a plurality of pixels, each of the plurality of pixels disposed to receive at least a portion of a plurality of the constituent wavelength signals provides a power reading for each constituent wavelength. Preferably, the TLP is lensed at one end, and recessed in a protective boot with stepped inner walls. The gap between the TLP and LVF is minimized to further enhance resolution and robustness.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A portable spectrometer device includes an illumination source for directing at a sample, and a tapered light pipe (TLP) for capturing light interacting with the sample at a first focal ratio and for delivering the light at a second focal ratio lower than the first focal ratio. A linearly variable filter (LVF) separates the captured light into a spectrum of constituent wavelength signals; and a detector array, including a plurality of pixels, each of the plurality of pixels disposed to receive at least a portion of a plurality of the constituent wavelength signals provides a power reading for each constituent wavelength. Preferably, the TLP is lensed at one end, and recessed in a protective boot with stepped inner walls. The gap between the TLP and LVF is minimized to further enhance resolution and robustness.

Abstract: A portable spectrometer device includes an illumination source for directing at a sample, and a tapered light pipe (TLP) for capturing light interacting with the sample at a first focal ratio and for delivering the light at a second focal ratio lower than the first focal ratio. A linearly variable filter (LVF) separates the captured light into a spectrum of constituent wavelength signals; and a detector array, including a plurality of pixels, each of the plurality of pixels disposed to receive at least a portion of a plurality of the constituent wavelength signals provides a power reading for each constituent wavelength. Preferably, the TLP is lensed at one end, and recessed in a protective boot with stepped inner walls. The gap between the TLP and LVF is minimized to further enhance resolution and robustness.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A method and apparatus for field spectroscopic characterization of seafood is disclosed. A portable NIR spectrometer is connected to an analyzer configured for performing a multivariate analysis of reflection spectra to determine qualitatively the true identities or quantitatively the freshness of seafood samples.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A portable spectrometer device includes an illumination source for directing at a sample, and a tapered light pipe (TLP) for capturing light interacting with the sample at a first focal ratio and for delivering the light at a second focal ratio lower than the first focal ratio. A linearly variable filter (LVF) separates the captured. light into a spectrum of constituent wavelength signals; and a detector array, including a plurality of pixels, each of the plurality of pixels disposed to receive at least a portion of a plurality of the constituent wavelength signals provides a power reading for each constituent wavelength. Preferably, the TLP is lensed at one end, and recessed in a protective boot with stepped inner walls. The gap between the TLP and LVF is minimized to further enhance resolution and robustness.

Abstract: A method and apparatus for field spectroscopic characterization of seafood is disclosed. A portable NIR spectrometer is connected to an analyzer configured for performing a multivariate analysis of reflection spectra to determine qualitatively the true identities or quantitatively the freshness of seafood samples.

Abstract: A variable optical filter is disclosed including a bandpass filter and a blocking filter. The bandpass filter includes a stack of alternating first and second layers, and the blocking filter includes a stack of alternating third and fourth layers. The first, second and fourth materials each comprise different materials, so that a refractive index of the first material is smaller than a refractive index of the second material, which is smaller than a refractive index of the fourth material; while an absorption coefficient of the second material is smaller than an absorption coefficient of the fourth material. The materials can be selected to ensure high index contrast in the blocking filter and low optical losses in the bandpass filter. The first to fourth layers can be deposited directly on a photodetector array.

Abstract: A portable spectrometer device includes an illumination source for directing at a sample, and a tapered light pipe (TLP) for capturing light interacting with the sample at a first focal ratio and for delivering the light at a second focal ratio lower than the first focal ratio. A linearly variable filter (LVF) separates the captured light into a spectrum of constituent wavelength signals; and a detector array, including a plurality of pixels, each of the plurality of pixels disposed to receive at least a portion of a plurality of the constituent wavelength signals provides a power reading for each constituent wavelength. Preferably, the TLP is lensed at one end, and recessed in a protective boot with stepped inner walls. The gap between the TLP and LVF is minimized to further enhance resolution and robustness.