A method of generating subnanosecond pulsed laser light

Abstract

The invention discloses a method for generating subnanosecond pulse laser. The method is applied to a pressurized electro-optic Q-switched laser. The method includes: applying a square wave drive signal with a peak voltage greater than a quarter wave voltage to the Pockels cell in the electro-optic Q-switched laser through a Q switch drive module. During the time that the driving signal increases from 0 to the peak voltage, the electro-optic Q-switch changes from the off state to the on state and then to the partially open state. When the Q switch is in the off state, the laser gain medium absorbs the pump light to achieve population inversion and accumulation; when the Q switch is in the partially open state, the intracavity laser oscillates back and forth in the resonator, and outputs pulses through the output coupling mirror and polarizer respectively. laser. The intracavity oscillating laser is exhausted in a very short time, so that the pulse width of the output laser is compressed, and the sub-nanosecond pulse laser output is realized.

Description

Technical field [0001] The invention relates to the field of laser technology, in particular to a method for generating sub-nanosecond pulsed laser light. Background technique [0002] The pressurized electro-optic Q-switched pulse laser is generally composed of gain medium 5, input mirror 4, output mirror 9, Pockels cell 7, quarter wave plate 8, polarizer 6 and pump source 1. The basic structure is as figure 1 Shown. The main axis of the quarter wave plate 8 and the direction of the polarizer 6 are at an angle of 45 degrees. The Pockels cell 7 and the quarter wave plate 8 form an electro-optic Q switch and are used to control the polarization direction of the beam in the cavity . When the voltage applied by the electro-optic Q-switch driving source 3 to the Pockels cell in the electro-optic Q-switch is 0, the rotation angle of the polarization direction of the intracavity beam after passing through the Q-switch twice is 90°, and the resonant cavity is in a state of high loss. ...

AI Technical Summary

Problems solved by technology

Since the length of the resonator is limited by the size of the gain medium and the components in the cavity, it is difficult to achieve sub-nanosecond high-energy laser output under the condition of high repetition rate by using a short resonator length.

Using the method of increasing the transmittance of the output mirror, although the laser pulse width can be narrowed by increasing the pump power, there are problems such as high threshold, easy thermal cracking of the laser crystal, and broadening of the rising edge of the laser pulse.

The method of active and passive double Q-switching needs to introduce additional insertion components, resulting in an increase in the length of the resonant cavity, and it is also difficult to achieve sub-nanosecond laser output

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