Methods and systems of hyperspectral imaging systems employing fabry-pÉrot (FP) filter arrays
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Solution Overview
Problem
Conventional hyperspectral imaging systems face significant loss of aperture efficiency due to the slit-spectrometer approach and require additional apparatus for spectral discrimination, limiting light throughput and increasing complexity.
Innovation Solution
The development of active hyperspectral filter arrays using d33 and d31 piezoelectric materials, configured with electrodes to vary optical path length and separate wavelength channels, enabling controlled modulation and spectral separation within a compact and simplified architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a slit-spectrometer approach is used for spectral discrimination, then spectral information can be separated and assessed, but aperture efficiency is significantly lost due to spatial filtering at the slit plane
Solution Approach 1:
The system segments the spectral discrimination function into multiple independent Fabry-Pérot filter elements arranged in a focal plane array, where each element can be independently controlled to transmit specific wavelength bands, eliminating the need for a single slit that blocks most light
Solution Approach 2:
The invention transitions from a 1D slit-based spectral discrimination to a 2D focal plane array where spectral separation occurs through the spatial arrangement of multiple tunable filters, adding a dimensional aspect that allows simultaneous spectral analysis across multiple wavelength channels without sacrificing aperture
2Measurement precision
If conventional imaging spectrometers are used to accommodate the spectral variable, then spectral information can be acquired, but additional apparatus is required which increases system complexity
Solution Approach 1:
The invention merges the spectral filtering function directly into the focal plane array structure, combining the imaging detector with tunable Fabry-Pérot filters in a single integrated component, thereby eliminating the need for separate imaging spectrometer apparatus
Solution Approach 2:
The focal plane array serves multiple functions simultaneously: it acts as both the imaging detector and the spectral filter, with each pixel element capable of independently selecting wavelength bands, making the system multi-functional without requiring additional dedicated spectral discrimination apparatus
3Measurement precision
If filters are used to separate wavelength channels, then spectral information can be discriminated, but light throughput is limited to predetermined wavelength ranges
Solution Approach 1:
The system employs dynamically tunable Fabry-Pérot filters whose transmission characteristics can be adjusted in real-time by changing the cavity spacing through piezoelectric actuation, allowing the wavelength passbands to be dynamically reconfigured rather than fixed, thereby maximizing light throughput across different spectral regions of interest
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances light throughput, reduces system complexity, and allows for precise spectral discrimination, improving the efficiency and compactness of hyperspectral imaging systems while maintaining high selectivity and tunability.
Implementation Method 1
the d33 piezoelectric material is configured to display a piezoelectric effect along a same axis of a directed light used to obtain a controlled modulation
Implementation Method 2
each stacked similar piezoelectric element comprises an optically selective Fabry-Perot etalon
Data Source
AI summary
In one aspect, an active hyperspectral filter array includes a polished wafer comprising a d33 material, wherein the d33 piezoelectric material is configured to display a piezoelectric effect along a same axis of a directed light used to obtain a controlled modulation; wherein the polished wafer comprises: a front electrode on a front surface of the polished wafer, a back electrode on a back surface of the polished wafer, wherein the front electrode and the back electrode are configured such that an optical path length is variable by application of an appropriate electric field.