Thermal lens effect for optimizing a passively Q-switched 1064 nm laser

Abstract

We demonstrate the improvement of pulse characteristics of a passively Q-switched laser by utilizing the thermal lens effect of a saturable absorber (SA) inside the cavity. The experimental results show that the SA should be considered as a convex lens inside the cavity, whose position strongly improves output performance. A fourfold enhancement of the average output power is obtained, and the peak energy increases from 8.2 to 25 µJ. Theoretically, we calculate the thermal lens effect of the SA and the optimal position inside the cavity, which agree with the experimental results.

Thermal focal length determination of a laser crystal by modulating the pump source

“…Diode-pump solid-state (DPSS) laser is a very important laser source and has been broadly applied in various fields including laser engineering, quantum optics, metrology, military and defense [1,2]. However, in the development of DPSS lasers, the thermal lens effect of the laser crystals has always restricted the output power and affected the beam quality of the lasers, and has even caused damage to the laser crystals [3,4]. Therefore, a few methods were developed to determine the thermal lens effects of laser crystal and used in order to optimize the performance of the lasers and protect the laser crystals.…”

Modeling of end-pumped electrooptically Q-switched lasers with the influences of thermal effects and spatial mode matching

“…In recent years, laser-diode (LD) end-pumped solid-state Q-switched lasers, with the advantages of compactness, high efficiency, simplicity, and high reliability, have attracted considerable attention. [1][2][3][4] A laser source with a nanosecond order and kHz repetition rates has various applications in many fields such as laser ranging, 5) coherent telecommunication, 6) lidars, 7) information storage, 8) and remote sensing. 9) Unlike the passively Q-switched (PQS) pulse with instability due to the asynchronous bleaching of the absorber and the acoustic-optic Q-switched laser with a wide pulse duration, an electrooptically (EO) Q-switched laser can obtain a stable short laser pulse.…”