DFB laser frequency stabilization method based on current control

Abstract

The invention discloses a DFB laser frequency stabilization method based on current control, and the method comprises the steps: carrying out the wavelength-current modeling through employing the current tuning characteristics of a DFB laser and a genetic programming algorithm, so as to set the constant frequency DC work environment of the DFB laser; obtaining a saturated absorption spectrum signal based on the saturated absorption principle; obtaining an odd harmonic differential error signal containing frequency information through employing a phase sensitive detection principle, and carrying out the PID control parameter optimization of the error signal through employing the genetic algorithm. The method achieves the quick and accurate adaptive frequency locking control, gives consideration to the high precision of saturated absorption frequency stabilization, and can guarantee the long-time high precision and stability of the frequency of the laser.

Description

technical field [0001] The invention relates to the technical field of laser frequency stabilization, in particular to a current control-based DFB laser frequency stabilization method. Background technique [0002] Due to its compact structure and good shockproof performance, DFB lasers are usually used as pumping and detection lasers in atomic physics experiments. DFB laser is a direct carrier injection device, and DFB laser has good current tuning characteristics, so it is of great significance to study the relationship between injection current and frequency of DFB laser, and use this relationship for frequency stability control. [0003] Commonly used DFB laser frequency stabilization methods include Zeeman frequency stabilization, saturated absorption frequency stabilization, Faraday optical rotation frequency stabilization, etc. The common feature of these frequency stabilization systems is to design a PID control loop to build a servo control system. The traditional f...

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Problems solved by technology

[0003] Commonly used DFB laser frequency stabilization methods include Zeeman frequency stabilization, saturated absorption frequency stabilization, Faraday optical rotation frequency stabilization, etc. The common feature of these frequency stabilization systems is to design a PID control loop to build a servo control system. The traditional frequency stabilization PID servo control The frequency converter usually adopts the setting of empirical P and I parameter values ​​or manual adjustment of PI parameters for a long time to realize the frequency locking link, but this process is slow and the accuracy is low, so that the frequency cannot be locked quickly; and in the above several frequency stabilization methods, although The frequency stabilization accuracy of the saturated absorption method is high, but in the frequency stabilization experiment of the saturated absorption method, it is found that it is not easy to lock the frequency, and it is easy to lose the lock.

[0004] Prior art "R b Atomic Zeeman Modulation Frequency Stabilization Semiconductor Laser" and "Design of DFB Laser Frequency Stabilization System Combining Zeeman Effect and Saturable Absorption Technology" are both frequency stabilization methods that combine Zeeman frequency stabilization and saturation absorption frequency stabilization, and the control still uses The classic analog PID control method, although this method makes up for the problem of Zeeman frequency stabilization and Doppler background interference and low precision, when the current changes or the external temperature changes cause the laser output wavelength and current model to change, the control still does not guarantee optimal real-time control

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