Silicon-based multi-mode interference modulation Fourier transform spectral measurement method and system

Abstract

The invention discloses a silicon-based multi-mode interference modulation Fourier transform spectral measurement method and system. On the basis of maintaining the size of a highly compact silicon-based spectral device, by utilizing the propagation constant difference among various modes of a multi-mode waveguide, interference signals are generated and detected at the same time through various waveguide modes, so the sampling rate of interference modulation signals is greatly improved, the sampling law is followed, the performance of the recovered spectrum is improved, and high-resolution broadband high-performance silicon-based spectrum measurement is achieved.

Description

technical field [0001] The invention belongs to the field of Fourier transform spectrum detection, and in particular relates to a silicon-based multi-mode interference modulation Fourier transform spectrum measurement method and system. Background technique [0002] Spectral detection has become an important method for qualitative and quantitative analysis of material components, including infrared spectroscopy, Raman spectroscopy, and fluorescence spectroscopy. It has been applied in many fields such as material development, food safety, and environmental protection. [0003] Fourier transform spectrometer (Fourier-transform Spectrometer, FTS) has the principle advantages of high spectral resolution and high signal-to-noise ratio, and is recognized as an important device capable of implementing high-performance spectral detection. In order to further improve spectral detection in various Versatility and applicability in complex scenarios, the miniaturization of FTS has att...

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Problems solved by technology

First, use spectral reconstruction methods such as compressed sensing to break through the sampling law (Rayleigh criterion), but the spectrum to be measured is required to be sparse, and the applicable scenarios are limited. For details, see Podmore H, Scott A, Cheben P, et al. Demonstration of a compressive -sensing Fourier-transform on-chip spectrometer[J].Optics Letters,2017,42(7):1440-1443; Second, observe the Rayleigh criterion, change OPD through active thermo-optic effect physical modulation, and increase OPD sampling points , but it is not conducive to system stability and time resolution. For details, see Montesinos-Ballester M, Liu Q, Vakarin V, et al. On-chip Fourier-transform spectrometer based on spatial heterodyning tuned by thermo-opticeffect[J].Scientific Reports ,2019,9:14633

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