Nano-optic filter array based sensor
Inventors
Choi, Byung Il • Lee, Byounghee • Song, Min Kyu
Assignees
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Publication Number
US-9395473-B2
Publication Date
2016-07-19
Expiration Date
Abstract
A device such as a filter or reflector includes a conductive layer including a periodic pattern of elements. The elements have shapes and sizes configured such that a transmittance or reflectance spectrum of the conductive layer has a drop at a long-wavelength end. The elements have a period configured such that the spectrum has a dip at a Plasmon mode resonant wavelength. The spectrum further includes a peal—between the dip and the drop.
Core Innovation
The invention characterizes incident radiation by employing a spectrum sensor that includes a plurality of combinations of a filter device and a photodetector optically coupled to each filter device, where each filter device has a transmittance spectrum different from transmittance spectra of other filter devices. Different transmittance spectra provide different weighting to a spectrum of the incident radiation, and measured outputs are generated by detecting transmitted radiation from the respective filter device.
The invention generates an estimation of a spectral profile of the incident radiation from the measured outputs using an estimation method that utilizes the different weighting corresponding to the filter devices. In embodiments described, outputs are used together with a spectral response matrix, including matrix inversion or Moore-Penrose pseudoinverse and least squares estimation.
At least one filter device comprises a contiguous conductive layer in which the corresponding array of periodic patterns is embodied as apertures entirely laterally surrounded by the contiguous conductive layer. At least one filter device comprises two dielectric layers with the contiguous conductive layer disposed between them, and the contiguous conductive layer includes a plurality of apertures and gaps filled with a dielectric material that is the same as the two dielectric layers.
Claims Coverage
The independent claim is clm-00001 and it contains four inventive features.
Spectrum sensor with different filter-device transmittance spectra for weighting
A plurality of combinations of a filter device and a photodetector are optically coupled, each filter device having a transmittance spectrum different from transmittance spectra of other filter devices, so that different transmittance spectra provide different weighting to a spectrum of incident radiation and measured outputs are generated from transmitted radiation.
Contiguous conductive layer with apertures laterally surrounded by the conductive layer
At least one filter device comprises a contiguous conductive layer in which the corresponding array of periodic patterns is embodied as apertures entirely laterally surrounded by the contiguous conductive layer.
Two-dielectric-layer structure with conductive layer disposed between and filled apertures/gaps using matching dielectric
At least one filter device comprises two dielectric layers, the contiguous conductive layer is disposed between the two dielectric layers, and apertures and gaps in the contiguous conductive layer are filled with a dielectric material that is the same as the two dielectric layers to reduce numbers of dips and peaks in the spectrum and increase transmittance or reflectance.
Spectral-profile estimation using weighting corresponding to different filter-device transmittance spectra
An estimation of a spectral profile of incident radiation is generated from the measured outputs using an estimation method that utilizes the different weighting corresponding to the filter devices.
The claim coverage centers on estimating an incident radiation spectral profile using a spectrum sensor formed from multiple filter devices with different transmittance spectra coupled to photodetectors, including a contiguous conductive layer with periodic-pattern apertures and a two-dielectric-layer arrangement with the conductive layer disposed between dielectric layers and filled apertures and gaps.
Stated Advantages
reduces numbers of dips and peaks in the spectrum
increases transmittance or reflectance
includes a long-wavelength cutoff and a plasmon-mode dip with a peak between the dip and the cutoff
Documented Applications
Color mapping or interpretation of outputs as color tristimulus/color space values.
Monitoring vital/health signals in a wireless wearable monitoring context.
Indirect biochemical detection using a color-changing agent sensed via a plasmonic sensor-filtered response.
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