Multi-Object Silicon Photonic Spectrometer

A multi-object silicon photonic spectrometer with N input ports is proposed and realized by integrating a multi-channel passband optical filter (POF), a tunable narrow-band optical filter as well as a calibration-free N x 1 Mach-Zehnder switch (MZS) array. Here, the multi-channel POF consisting of a multimode waveguide grating (MWG) and a mode (de)multiplexer is used to achieve a broadened working window and an enhanced dynamic range for the present spectrometer, while the narrow-band optical filter is realized with a thermally-tunable Euler micro-ring resonator (EMR) for achieving a very high spectral resolution. The introduction of the N x 1 MZS enables the time-division-multiplexed (TDM) spectrum analysis for multiple objects. In this paper, a multi-object silicon photonic spectrometer with 16 input ports is demonstrated with an on-chip loss of less than 3 dB and inter-channel crosstalk as low as -25 dB. This multi-object spectrometer can be used to analyze the spectra of 16 objects one by one by setting the 16 x 1 MZS, the resolution is as high as 50 pm, and the working window is approximate to 84 nm.