Recent advances in Fourier-transform waveguide spectrometers

We present the development of a compact planar waveguide Fourier-transform spectrometer for high-resolution and high-throughput spectroscopy. The prototype device is designed to monitor the water vapor absorption band near λ = 1364 nm in the atmosphere from an Earth-orbiting satellite. The instrument is fully static (i.e. no moving parts) and it is based on a unique slab waveguide Fourier-transform spectrometer concept implemented with silicon-on-insulator (SOI) technology. The spectrometer input is formed by an array of N independent waveguide apertures, thereby significantly (Nx) increasing light gathering capability (étendue) compared to conventional single-aperture devices. We also discuss a practical implementation of the multi-aperture concept based on an array of surface grating couplers.