Silicon-on-insulator spatial heterodyne spectrometer chip for the mid-infrared

We demonstrate fur the first linio a silicon-on-insulator spatial hoterodyne waveguide spectrometer chip operating in i ho mid-infrared. The device comprises a MMI splitting tree, followed by an array of 42 Mach-Zehnder interferometers with linearly increasing optical path differences. The fabricated device was characterized in the 3717-3772 nm wavelength range by retrieving the spectral line of a quantum cascade laser line, with a wavelength resolution of 2.8 nm.