[A novel near-infrared spectra detection system based on MEMS grating light modulators].

A novel near-infrared spectrum detection system based on grating light modulators is proposed in the present paper. A new spectrum detection method that combines MEMS grating light modulators with a single near infrared detector is applied in the system, which can avoid using costly near infrared detector array. Firstly, the optical structure of the spectra detection system was designed. Secondly, the spectra detection principle of this system was addressed in detail that with a series of voltages actuated on the grating light modulators array, the optical energy of each wavelength is reflected onto the single near-infrared detector by corresponding grating light modulator pixel orderly and the transmission spectra can be acquired after a scanning period. Finally, the grating light modulators array device was fabricated by surface micromachining processing and a near-infrared spectra detection system was set up to test the key parameters such as resolving power, wavelength accuracy, system stability and response characteristics of grating light modulators. The experimental results illuminated that the spectrum range of this spectra detection system is from 1 320 to 1 400 nm, the resolving power is below 10 nm, the wavelength accuracy is within 1 nm, the stability of the system is below 0.5% and the response frequency is 5 kHz. The results of theory analysis and experiments demonstrated the feasibility of the spectra detection system. It could give theoretical and experimental guidance to the design and fabrication of miniature near-infrared spectrometer based on grating light modulators.