Polarization insensitive arrayed-input spectrometer chip based on silicon-on-insulator echelle grating

Abstract

We demonstrate a polarization insensitive arrayed-input spectrometer using echelle diffraction grating (EDG) for hyperspectral imaging. The EDG consists of 65 input waveguides and 129 output waveguides, allowing spectral measurements of 65 image pixels at a time when used in combination with a micro-electromechanical system micro mirror array. The spectral resolution reaches 7.8 nm for wavelengths ranging from 1250 to 1700 nm. The measured loss is −2 dB, and the crosstalk is lower than −20 dB. The 3 μm silicon-on-insulator platform provides the device with polarization insensitive characteristics. The chip size is only 6 mm×10 mm.