Fig. 2
From: Scalable miniature on-chip Fourier transform spectrometer for Raman spectroscopy
The multi-aperture waveguide-based Fourier transform spectrometer. a Schematic top-view of edge-coupled multi-aperture waveguide-based Fourier transform spectrometer (FTS), illustrating the operation of the ultra-compact interferometers. b Cross-sectional schematic of an interferometer, showing its back-reflector enhanced vertical grating coupler (VGC) and termination mirror. c Pictures of the 200 mm SiN photonics wafer and one of the FTS chips, with a Raman spectrum in the background. d Scanning electron micrograph of the cross-section of an interferometer, near its aluminum mirror termination
