Spectral calibration and radiometric calibration is an important part in the data processing of the windowing Fourier transform imaging spectrometer, it can ensure that the spectral curve output from spectrometer are more closely to target spectrum. The main idea of spectral calibration is using a monochromatic source whose wavelength is known, in the same way, radiometric calibration can be achieved by using radiation source whose radiation characteristic is known.
In this paper, we propose a set of methods of spectral calibration and radiometric calibration. In order to carry out spectral calibration, we use monocharomator to scan several sample points near the position of every spectral channel of imaging spectrometer, and then we employ Gaussian fitting function to determine the central wavelength and bandwidth of every spectral channel. In order to carry out radiometric calibration, we employ panchromatic light source and integrating sphere, at the position of every spectral channel of imaging spectrometer, we measure the response ability of spectrometer to radiation. The calibration accuracy is carefully analyzed. Experimental results show that calibration accuracy meet the given requirements.
A kind of infrared Liquid Crystal Light Valve (IRLCLV) based on polymer/liquid
crystal is introduced to improve IRLCLV's response. The structure, technical process and
conversion characteristics in visible-infrared image system were studied. The IRLCLV shows fast
response and weak dependency with thickness. Also the device has simple fabricating process and
high reliability. In visible-infrared image system, 100Hz frame rate and 10lp/mm spatial resolution
were measured. It will provide wide dynamic range and high frame rate IR scenes for optic-electro
simulation and testing systems.
A kind of spatial light modulator using sheared polymer network liquid crystal (SPNLC) is presented. The
SPNLC shows a fast response and weak thickness dependency. The SPNLC cell is fabricated by exposing the mixture of
E7 liquid crystal and monomer NOA65 under ultraviolet light. A sheared force is applied to the cell to align the liquid
crystal domains, decreasing response time and reducing light scattering. A SPNLC sample of d=13μm with about 3ms
response time was measured at λ=632.8nm. For another sample of d=20μm reflective infrared spatial light modulator using SPNLC, when the black body of readout radiation was 600°C, response time with about 8ms at λ=10.6μm and the maximum difference in temperature with more than 80°C at 8~14μm were measured.