Realization of rapid debugging for detection circuit of optical fiber gas sensor: Using an analog signal source

Abstract

An optical fiber gas sensor mainly consists of two parts: optical part and detection circuit. In the debugging for the detection circuit, the optical part usually serves as a signal source. However, in the debugging condition, the optical part can be easily influenced by many factors, such as the fluctuation of ambient temperature or driving current resulting in instability of the wavelength and intensity for the laser; for dual-beam sensor, the different bends and stresses of the optical fiber will lead to the fluctuation of the intensity and phase; the intensity noise from the collimator, coupler, and other optical devices in the system will also result in the impurity of the optical part based signal source. In order to dramatically improve the debugging efficiency of the detection circuit and shorten the period of research and development, this paper describes an analog signal source, consisting of a single chip microcomputer (SCM), an amplifier circuit, and a voltage-to-current conversion circuit. It can be used to realize the rapid debugging detection circuit of the optical fiber gas sensor instead of optical part based signal source. This analog signal source performs well with many other advantages, such as the simple operation, small size, and light weight.

Keywords

Optical fiber gas sensor / detection circuit / analog signal source / rapid debugging

References

[1] Zhang A. Study on spectrum absorptive fiber optic gas sensors, 2005, China: University of Technology

[2] Liu D. Research on the driving control system of Steady-frequency for light source in optical fiber gas sensing, 2006, China: Huazhong University of Science and Technology

[3] Zhang Y, Chang J, Wang Q, Zhang S, Song F. The theoretical and experimental exploration of a novel water vapor concentration measurement scheme based on scanning spectrometry. International Conference on Electronics and Optoelectronics 2011, 2011 29-31.

[4] Wang Q, Chang J, Zhu C, Li C, Song F, Liu Y N, . Detection of water vapor concentration based on differential value of two adjacent absorption peaks. Laser Physics Letters, 2012, 9(6): 421-425.

[5] Sun Y, Lu X. Research on improving sensitivity of the characteristic spectrum in micro-gas monitor. Spectroscopy and Spectral Analysis, 2010, 30(7): l890-1893.

[6] Wang Q, Chang J, Zhu C, Liu Y, Lv G, Wang F, . High-sensitive measurement of water vapor: shot-noise level performance via a noise canceller. Applied Optics, 2013, 52(5): 1094-1099.

[7] Qi J, Dong X, Zheng J, Lin G. An algorithm of filtering background noise of optical fiber gas sensor. Chinese Journal of Lasers, 2011, 38(11): 1105008-1-1105008-6.

[8] Zhang S, Wang Q, Zhang Y, Song F, Chen K, Chou G, . Water vapor detection system based on scanning spectra. Photonic Sensors, 2012, 2(1): 71-76.

[9] Rothman L S, Gordon I E, Barbe A, Benner D C, Bernath P F, Birk M, . The HITRAN 2008 molecular spectroscopic database. Journal of Quantitative Spectroscopy and Radiative Transfer, 2009, 110(9–10): 533-572.

[10] Hobbs P C D. Shot noise optical measurement at baseband with noisy lasers. Proc. SPIE, 1990, 1376, 216-221.

[11] Haller K L, Hobbs P C D. Double beam laser absorption spectroscopy: shot noise-limited performance at baseband with a novel electronic noise canceller. Proc. SPIE, 1991, 1435, 298-309.