A microspectrometer with dual-signal spectral reconstruction
摘要
Computational spectrometers with small footprints can be integrated with other devices for use in applications such as chemical analysis, medical diagnosis and environmental monitoring. However, their spectral resolution is limited because conventional photoelectric detectors only measure an amplitude-dependent response to incident light. Here we show that a deformable two-dimensional homojunction can be used to create a microspectrometer with dual-signal spectral reconstruction. The semifloating molybdenum disulfide homojunction exhibits a giant electrostriction effect through which the kinetics of photo-generated carriers can be manipulated via an in-plane electric field generated by gate voltage. By leveraging the tunability of both amplitude and relaxation time of the photoelectric response, a dual-signal response can be used with a deep neural network algorithm to reconstruct an incident spectrum. Our dual-signal microspectrometer has a footprint of 20 × 25 µm2, offers a resolution of 1.2 nm and has a spectral waveband number of 380, which is comparable to benchtop spectrometers.