Common NICE-OHMS (Noise-immune Cavity-Enhanced Optical Heterodyne Molecular Spectroscopy) system for detecting sub-Doppler spectroscopy

Abstract

The invention belongs to the technical field of laser spectrum and provides a common NICE-OHMS (Noise-immune Cavity-Enhanced Optical Heterodyne Molecular Spectroscopy) system for detecting sub-Dopplerspectroscopy. The common NICE-OHMS system comprises a single side band phase modulator, an erbium-doped optical fiber amplifier and a voltage-controlled oscillator, wherein the voltage-controlled oscillator is used for driving the single side band phase modulator; a light beam emitted by a laser device passes through the single side band phase modulator, the erbium-doped optical fiber amplifier,an electro-optic modulator, a mode matching lens, a 1 / 2 wave plate, a polarized beam splitter prism and 1 / 4 wave plate in sequence and then enters a high-fineness cavity; a pre-cavity reflection signal of the high-fineness cavity is detected through a first detector and a reflection signal detected by a second detector is processed through a PID (Proportion Integration Differentiation) servo loopand then a feedback signal is output to the voltage-controlled oscillator so as to control the driving frequency of the voltage-controlled oscillator; furthermore, the off-set frequency of the singleside band phase modulator is controlled to realize PDH locking of laser frequency. The common NICE-OHMS system can be compatible with various laser devices and the compatibility of the NICE-OHMS system is improved.

Description

technical field [0001] The invention belongs to the technical field of laser spectroscopy, in particular to a general NICE-OHMS system for detecting sub-Doppler spectra. Background technique [0002] Trace gas detection technology has been applied in all aspects of our life and production, such as environmental detection, industrial exhaust gas monitoring, pathological diagnosis, precision agriculture, outer space detection and chip manufacturing. As a new type of trace gas detection technology, absorption spectroscopy technology has the advantages of non-contact, high sensitivity, and real-time on-site detection compared with traditional electrochemical methods and gas chromatography. Noise Immune Cavity Enhanced Optical Heterodyne Molecular Spectroscopy (NICE-OHMS) technology is currently the most sensitive absorption spectroscopy detection technology in the world, and the latest detection sensitivity record is 2.2X10 -14 cm -1 , NICE-OHMS technology was proposed by Ye J...

AI Technical Summary

Problems solved by technology

[0006] PZT is used as the frequency control element inside the laser. Different lasers have different response characteristics. In order to achieve a good locking effect, it is necessary to set a special PID circuit for different lasers, which invisibly increases the complexity of the system and limits the NICE-OHMS system. compatibility

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