Measurement of the Spectral Characteristic Parameters of Linear Variable Filters

In order to accurately measure the spectral characteristic parameters of Linear Variable Filters (LVF), a method of measuring the transmission of LVF was presented. In this method, the spectral transmission at the measurement point was calculated by measuring the spectral signal of light source and transmitted light with a spectrometer. By adjusting the displacement platform, the spectral transmission at different positions was measured. Then the spectral characteristic parameters of LVF was obtained by data processing. The theoretical formula for measuring the spectral transmittance was deduced. The simulation results show that the accuracy of this method decreases as the linear dispersion increases. When the linear dispersion is less than 1.5 nm·mm^-1, the errors of the measured center transmission and bandwidth are less than 0.4%. An experimental setup was built to test the spectral parameters of a linear variable filter.