Broadband Digital Fourier Transform Spectrometer for On-Chip Wavelength Monitoring in the 2.3-$mu$m Wavelength Range

摘要

We demonstrate a broadband digital Fourier Transform (dFT) spectrometer addressing wavelength monitoring applications in the 2.3-mu m wavelength range. The spectrometer is built in a silicon-on-insulator platform and the design allows its fabrication with CMOS-compatible tools. We report an operating bandwidth of 130 nm around 2.3 mu m wavelength using an efficient algorithm for sparse spectra to retrieve the wavelength with an accuracy of 100 pm. The spectrometer can also resolve two laser lines up for dFT spectrometers, which takes advantage of the sparse nature of the spectrum.