Abstract

It was recently demonstrated that by adding a filter array to photodetector array, a very compact wavelength-multiplexed spectrometer can be achieved [1, 2]. These previous efforts have had both strengths and weaknesses, however. In [1], the filter array comprised etalons with different thicknesses fabricated by a multi-step process. In [2], the filter array comprised quantum dots spotted onto the device with a pipette. Here, we study a spectrometer comprising an array of silicon nanowire (Si NW) photodetectors, formed above an array of planar photodetectors. This device would have manufacturing advantages, being based on Si technology and with all NWs defined in a single lithography step. The NWs would act as photodetectors (converting absorbed light to photocurrent) but would also filter the light transmitted onto the planar photodetectors. After measurement of the photodetector currents, the spectrum of light impinging on the device would be reconstructed numerically.

© 2017 IEEE