A method and device for controlling and stabilizing the light intensity of a broadband light source

Abstract

The invention discloses a method and device for controlling the light intensity of a broadband light source to be stable. The method includes the steps that a convergent lens and a one-into-two type optical fiber bundle are used for collecting light emitted by the broadband light source, the light is used as feedback light, a narrowband bandpass filter set enables the feedback light to be divided into a plurality of wave bands, a photoelectric detector is used for detection to obtain feedback light signals at the positions of a plurality of wave lengths, the feedback light signals are compared with expected feedback light signals at the positions of corresponding wave lengths, difference values are worked out, a total difference value is calculated according to all the difference values, a control system automatically regulates the light intensity output by the light source according to the total difference value, and therefore the light intensity of the light source is made to be stable. The device is mainly composed of the broadband light source, the lens, the one-into-two type optical fiber bundle, a filter wheel, a direct-current motor, a driving circuit of the direct-current motor, a position detection circuit, a photoelectric conversion circuit, a voltage amplification circuit, a single-chip microcomputer control system and the like. According to the method and device for controlling the light intensity of the broadband light source to be stable, the problem that in the prior art, control over the stability of light intensity of a broadband light source has a larger error is solved, and stable light emitting of the broadband light source in an optical system is guaranteed.

Description

technical field [0001] The invention relates to a method and a device for controlling the light intensity of a light source, more specifically, a method and a device for controlling the stability of the light intensity of a broadband light source. Background technique [0002] Spectral detection technology is a technology that uses the characteristic absorption of substances in the corresponding band to determine the type and content of substances, such as differential absorption spectroscopy, broadband cavity enhanced absorption spectroscopy, laser-induced fluorescence spectroscopy, laser-induced breakdown spectroscopy, etc. In the detection system based on spectral detection technology, the light source is an indispensable optical device. From the perspective of the bandwidth of the light source, there are two main types of light sources used in this technology: one is broadband light sources, such as xenon arc lamps, deuterium lamps, etc.; the other is narrow-band light s...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method and device for controlling the stability of the light intensity of the broadband light source in view of the problem of relatively large errors in the prior art of stable control of the light intensity of the broadband light source

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