High-speed mid-infrared spectrometer based on wavelength-swept quantum cascade laser using asynchronous-signal method
Abstract
A high-speed mid-infrared spectrometer using a wavelength-swept, pulsed quantum cascade laser (QCL) as the light source is introduced in this study. The QCL uses a microelectromechanical-system (MEMS)-based scanning grating to sweep the wavelength range of the pulsed light. To obtain a continuous spectrum from a comb-shaped spectrum, we investigated an asynchronous-signal method that does not require phase-shift adjustment using a function generator. The measurement speed of the proposed system is improved and reaches a maximum of 20 ms, which is 100 times faster than that of the conventional synchronous-signal system. Thus, the QCL spectra can be obtained in almost real time, which is beneficial for analyzing several fast reaction processes. Compared with Fourier transform infrared (FTIR) systems, the proposed high-speed mid-infrared spectrometer is smaller and provides measurements faster. Owing to its advantages, the QCL system can be employed in several applications that require mid-infrared spectrum sensing technology to replace or complement FTIR systems.
- Publication:
-
Optics Laser Technology
- Pub Date:
- May 2022
- DOI:
- 10.1016/j.optlastec.2021.107800
- Bibcode:
- 2022OptLT.14907800C
- Keywords:
-
- QCL;
- quantum cascade laser;
- FTIR;
- Fourier transform infrared;
- EC-QCL;
- external-cavity-type QCL;
- MEMS;
- microelectromechanical system