Frequency locking device and locking method based on tunable laser absorption spectrum

Abstract

The invention discloses a frequency locking device and a locking method based on tunable laser absorption spectrum. The device includes a laser (1), an optical fiber (13), a collimating optical fiber (2), a scattered light collection lens (3), a photodetector (4), a temperature and current control component (5) and a frequency stabilization component (16), wherein , the frequency stabilization part (16) is a lock-in amplifier device (9), a data acquisition analysis device (10), an analog PID device (8), an operational amplifier device (7) and an addition device (15) connected in series, and a signal generation Device (6); the method is to adopt the modulation of triangular wave superimposed sine wave to the laser and the spacing between the two absorption peaks produced by the rising edge and falling edge in the scattered light signal containing gas absorption information received as variable value, draw The frequency stabilization feedback control signal stabilizes the frequency on a specific absorption peak. It can be widely used to detect the composition and content of substances in the atmosphere.

Description

technical field [0001] The invention relates to a frequency locking device and a locking method, in particular to a frequency locking device and a locking method based on tunable laser absorption spectrum. Background technique [0002] With the continuous development of social economy, environmental problems have become increasingly prominent. In order to effectively monitor and predict environmental pollution, people have made unremitting efforts, trying to detect the composition and content of substances in the atmosphere through laser spectroscopy, such as Chinese invention patent specification CN 100510673 C on July 8, 2009 A laser remote sensing detection device and detection method for natural gas pipeline leakage are announced. The device described in this patent specification includes a laser connected to an optical fiber and a detector electrically connected to a control processor. The output spectrum of the laser is infrared. At the focal point of the lens, the c...

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Problems solved by technology

Although this device and its method can be used for laser remote sensing detection of natural gas pipeline leakage, there is also a problem that in actual detection applications, especially in the process of long-term continuous detection, the output frequency of the laser is extremely susceptible to changes in the external environment. For example, the influence of temperature, humidity, vibration, etc. causes the defect of frequency drift, especially the influence of the change of external environment temperature on the output frequency of the laser is particularly serious.

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