Fig. 3: Fabricated spectrometer and its calibration.
From: Integrated reconstructive spectrometer with programmable photonic circuits
a Microscope image of the fabricated on-chip spectrometer in a 6-stage design with enlarged views of a MZI stage and a directional coupler. b Photograph of the photonic chip wire bonded to a customized PCB board. An UHNA-fiber array is used for the optical coupling. c Normalized transmission matrix of the programmable spectrometer with 729 channels. d Transmission spectra of several representative sampling channels, exhibiting the pseudo-random fluctuations in the wavelength domain. e The calculated spectral auto-correlation function between 729 channels with a δλ of 0.75 nm.
