VCSEL (vertical cavity surface emitting laser) laser tube parameter automatic adjustment method for CPT (coherent population trapping) magnetometer system

Abstract

The invention discloses a VCSEL (vertical cavity surface emitting laser) laser tube parameter automatic adjustment method for a CPT (coherent population trapping) magnetometer system. The method comprises the following steps of: on the basis of table temperature of an atomic gas chamber, through increasing driving current of the laser tube step by step and detecting light intensity, determining the range of scanning current; increasing the laser tube temperature step on the basis of initial working temperature, scanning triangular wave driving current repeatedly and searching for an absorption spectrum line in whole range; after the absorption spectrum line is read out for the first time, accurately locking the current value of the absorption spectrum line under the current working temperature condition by adjustment current, finely adjusting the temperature step, and adjusting the absorption spectrum line to the optimal position; recording the current laser tube working parallel, so as to finish the whole VCSEL laser tube parameter automatic adjustment process. By utilizing the laser tube parameter automatic adjustment method, the test of the VCSEL laser tube and set of working parameters are convenient, and the working efficiency and performance of whole machine are improved.

Description

Technical field [0001] The invention relates to a method for automatically adjusting parameters of a VCSEL laser tube, and belongs to the field of magnetic field measurement. Background technique [0002] Magnetic field measurement can be used in fields such as geophysical research, oil and gas and mineral exploration, military defense, medical diagnosis, geological survey, and archaeological research. Traditional magnetometers used for magnetic field measurement include fluxgate magnetometer, proton precession magnetometer, optical pump magnetometer, superconducting quantum interference magnetometer, etc. However, the above-mentioned magnetometers are currently unsatisfactory in terms of volume, power consumption, measurement range and accuracy. For example, the probe part of the fluxgate magnetometer is mostly made by winding a coil on a magnetic core with high permeability. , The volume and weight are large, and the measurement accuracy is low; the proton precession magnetome...

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Problems solved by technology

[0003] Although the VCSEL laser tube has the characteristics of small size, good beam directionality, high dynamic modulation frequency, and relatively fast response, due to the existence of individual differences, the operating temperature and operating current required for each VCSEL laser tube are not the same. At present, for the CPT magnetometer system, the method of manually adjusting the parameters of the VCSEL laser tube is generally used before the magnetic field measurement. This method is inefficient and requires multiple attempts to adjust the parameters, and the final parameters may not be the best parameters.

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