Filter-based interrogation unit for optical wavelength shift sensors

Abstract

We present a filter-based spectrometer consisting of a dielectric thin film filter with a lateral-spectral transmission gradient (linear variable filter) and a position detector which allows high resolution in wavelength shift registration. The resolving capacity of two interrogation unit variants (with segmented and homogeneous position detector, respectively) is examined using a monochromatic tunable light source. On the basis of the obtained results, we discuss several advantages and drawbacks of this interrogation approach