Abstract

Continuously high-speed spectroscopic gas detection with a wide spectral span has a long time been a challenge. We propose a method based on an extended optical linear chirp chain (EOLCC) for gas spectrum measurement with a fast acquisition rate and a broad bandwidth. The basic optical linear chirp (OLC) unit moves a fixed frequency when it passes through an optical loop containing a dual-parallel Mach-Zehnder modulator driven by a microwave signal. This method is demonstrated by monitoring a high-speed flow process of acetylene gas under normal pressure, achieving a spectral bandwidth of 88 GHz, a repetition frequency of 0.53 MHz, a 100% duty cycle, and a frequency-chirping linearity error of 5.2 × 10⁻⁵. Our proposed method based on the EOLCC is expected to have a repetition frequency on the MHz order, showing great potential in the development of high speed optical gas sensors.

Rapid spectroscopic gas sensing using optical linear chirp chain

Xiutao Lou, Ziyue Yuan, and Yongkang Dong
Opt. Express 27(9) 13160-13171 (2019)

Multipoint dispersion spectroscopic gas sensing by optical FMCW interferometry

Xiutao Lou, Yue Wang, and Yongkang Dong
Opt. Lett. 46(23) 5950-5953 (2021)

Chirped-pulse terahertz spectroscopy for broadband trace gas sensing

Eyal Gerecht, Kevin O. Douglass, and David F. Plusquellic
Opt. Express 19(9) 8973-8984 (2011)

Multi-point spectroscopic gas sensing based on coherent FMCW interferometry

Xiutao Lou, Yabo Feng, Chen Chen, and Yongkang Dong
Opt. Express 28(6) 9014-9026 (2020)

Segmented chirped-pulse Fourier transform submillimeter spectroscopy for broadband gas analysis

Justin L. Neill, Brent J. Harris, Amanda L. Steber, Kevin O. Douglass, David F. Plusquellic, and Brooks H. Pate
Opt. Express 21(17) 19743-19749 (2013)