Laser circuit of photoacoustic cell unit

Abstract

The invention discloses a laser circuit of a photoacoustic cell unit which comprises a power supply circuit for supplying power and a single-chip microcomputer for processing, sending and receiving signals,, wherein the single-chip microcomputer is connected with the power supply circuit; a laser emission circuit which comprises a semiconductor laser used for obtaining laser with a specific wavelength, wherein the laser emission circuit is provided with a first terminal, a second terminal and a third terminal; a current control circuit which is used for adjusting an input current of the laseremission circuit; a temperature adjusting circuit which is used for adjusting the temperature in the laser emission circuit. According to the laser circuit disclosed in the invention, the laser emitted by the semiconductor laser is stabilized at a wavelength and periodically changes within a certain range of the wavelength, a high-quality light source condition is provided for a photoacoustic spectrum detection test, and the detection precision is ensured.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a laser circuit of a photoacoustic pool unit. Background technique [0002] Photoacoustic spectroscopy is a new technology for studying the absorption spectrum of substances. It has become an important branch of molecular spectroscopy. The principle is that substances will be excited when they absorb light of a specific wavelength. Transition or non-radiative transition, but the transition will generate heat in this process; we put the substance in a closed container, so that the light absorbed by the substance is stable at a wavelength and changes periodically within a certain range of this wavelength, then the container The pressure fluctuation also changes periodically; since the frequency of the modulated light is generally in the audio frequency range, the pressure fluctuation becomes a sound wave, which can be perceived by the acoustic sensor; the acoustic signal perceive...

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Problems solved by technology

[0003] Among them, light is one of the key factors affecting the above experiments. It is very important to obtain a light with a periodic and stable wavelength. In the prior art, a laser transmitter is generally used to emit laser light into a confined space for material detection, but Since the laser emitted by existing lasers will be affected by temperature, it is difficult to control the emitted laser to be stable at one wavelength and to change periodically within a certain range of this wavelength, thus affecting the accuracy of detection

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