Multi-wavelength external cavity laser emission device for fluorescence suppression of Raman spectrometer

Abstract

The invention discloses a multi-wavelength external-cavity laser emitting device for fluorescence suppression of Raman spectrometers, which is characterized in that two or more laser diodes are connected and driven to be turned on and off independently through a power switching circuit, and each laser diode passes through a corresponding quasi- The straight lens outputs collimated beams, and an included angle δ is preset between adjacent collimated beams. These collimated beams are finally diffracted by the same grating to form output beams that exit directly at different diffraction angles and return along the original path to the diffracted beams that participate in the internal mode competition of the resonator inside the corresponding laser diode; the output beams are finally converged by a fiber coupling lens To the fiber combiner for wavelength output. The invention adopts circuit switching wavelength output, which eliminates the unreliability and possible errors of conventional mechanical adjustment, makes the tuning structure simpler and more stable, ensures the high stability of the output wavelength, and has strong repeatability of the wavelength output during actual operation. Greatly improve tuning accuracy.

Description

technical field [0001] The invention relates to an external-cavity laser emitting device, in particular to a multi-wavelength external-cavity laser emitting device used for fluorescence suppression of a Raman spectrometer. Background technique [0002] At present, Raman spectroscopy is widely used in field detection, drug analysis, pesticide detection and other fields. However, in the process of detecting pesticides, drugs, explosives, etc., Raman spectra are interfered by strong fluorescence. The Raman light intensity is so much smaller than the fluorescence intensity that it is overwhelmed by the fluorescence and cannot detect the Raman spectrum. Therefore, it is necessary to suppress fluorescence in order to efficiently detect Raman spectrum. [0003] At this stage, there are many methods to suppress fluorescence, the main method is baseline correction. Baseline correction is to fit the fluorescent background in the spectrogram through a specific algorithm and subtract...

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Problems solved by technology

[0007] The purpose of the present invention is to provide a multi-wavelength external cavity laser emission device for fluorescence suppression of Raman spectrometers, which is based on the principle of frequency shift excitation, and can overcome the complex tuning structure, poor stability, and weak output wavelength repeatability of known laser emission devices , The disadvantage of inconvenient adjustment for multi-wavelength switching

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