Compact multichannel high-resolution micro-electro-mechanical systems-based interrogator for Fiber Bragg grating sensing.

ABSTRACT

We propose a novel type of compact high-resolution multichannel micro-electro-mechanical systems (MEMS)-based interrogator, where we replace the linear detector with a digital micromirror device (DMD). The DMD is typically cheaper and has better pixel sampling than an InGaAs detector used in the 1550 nm range, which leads to cost reduction and better performance. Moreover, the DMD is a 2D array, which means that multichannel systems can be implemented without any additional optical components in the interrogator. This makes the proposed interrogator highly cost-effective, particularly for multichannel systems. The digital nature of the DMD also provides opportunities for advanced programmable Hadamard spectroscopy, which, without significant penalties, can greatly improve the wavelength fit resolution. Our results show that DMDs can be used in high-resolution spectroscopy and for Fiber Bragg grating (FBG) interrogation.