Device for improving pulse energy stability of ultrafast laser amplifier and control method thereof

Abstract

The invention relates to a device for improving pulse energy stability of an ultrafast laser amplifier. The device comprises a laser oscillator, a signal generator, a menu controller, a pump laser, a laser amplifier and a feedback controller, wherein the feedback controller is connected with the signal generator, the pump laser and the laser amplifier and used for monitoring pulse energy of the laser amplifier in real time and outputting a feedback signal to adjust delay of oscillation starting time of a laser cavity of the laser amplifier relative to pumping laser pulse. Any light paths in an amplifier system are not required to be modified, the control of amplification laser pulse energy can be achieved only by using a circuit to control the delay, implementation is simple and easy, and the performance is reliable.

Description

technical field [0001] The invention relates to a control device and a method of an ultra-fast laser, in particular to a device and a control method for improving the pulse energy stability of an ultra-fast laser amplifier. Background technique [0002] The stability of the pulse energy output by an ultrafast laser amplifier is one of the important factors affecting the results of physical experiments. The pulse energy output by an ultrafast amplifier using chirped pulse amplification technology will be affected by many factors such as pump laser, seed laser, and amplifier cavity. factors. The current pump lasers mostly use commercial all-solid-state kilohertz laser sources, and their short-term and long-term pulse energy stability has been guaranteed. However, affected by factors such as laboratory temperature changes and mechanical deformation, even if the energy and direction of the seed laser output by the laser oscillator remain unchanged, the injection path of the see...

AI Technical Summary

Problems solved by technology

However, if you want to change the pulse energy of the seed laser, you need to insert some optical components before the seed laser is injected into the amplifier, which will inevitably increase the dispersion; if you change the injection direction of the seed laser, it may affect the spectral characteristics of the amplified laser pulse. Both will affect the pulse width of the amplified laser pulse

Adjusting the cavity mirror of the laser amplifier may change the direction of the amplified pulse laser beam

The linear relationship between the energy of the amplified laser pulse and the energy of the pump laser pulse is relatively obvious. Therefore, theoretically speaking, modulating the energy of the pump laser pulse is a very feasible solution to control the energy of the amplified laser pulse. However, the commonly used commercial pump Light sources such as Empower (manufactured by Libo, USA) and Evolution (manufactured by Coherent, USA) do not accept external control commands to control their pulse energy. Even if they are controlled by their own software, the range of pump energy change is not fine enough, so A simple command control method cannot play a role in precisely controlling the pulse energy of the amplifier

Another solution to control the energy of the pump laser pulse is to insert an optical modulation element similar to an acousto-optic crystal in the pump optical path, which can be controlled to quickly fine-tune the energy of the pump laser pulse, but due to the The energy and average power are generally high (energy greater than 10mJ, average power greater than 10W), and the power density of the laser beam transmitted through the modulated crystal is also high. The modulation element used must have a fairly high destruction threshold and must be well dissipated. Cooling treatment work, so this solution is not easy to implement, the structure is complex and the cost is high

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