Study on thermally induced depolarization of a probe beam by considering the thermal lens effect

Abstract

In this paper, we present an accurate theoretical description of the birefringence characteristics in a Nd : YAG rod by taking the thermal lens effect into account. Considering that the birefringence is strongly dependent on the distance away from the centre of a birefringent rod, the convergent features of an incident probe beam were first evaluated for a side-pumped laser rod. A segmental accumulation method was then employed to calculate the total phase shift between the radial and the tangential components of polarization of a converged probe beam. The theoretical conclusions were compared with the measured results in both the degree of depolarization and the spatial birefringent distribution of a transmitted He–Ne laser beam. The experimental results are in good agreement with the theoretical ones so that we believe the algorithm given in this paper should be effective for the construction of a high-powered laser or amplifier system.

Hybrid master oscillator power amplifier system providing 10 mJ, 32 W, and 50 MW pulses for optical parametric chirped-pulse amplification pumping

“…Additionally, Nd:YAG under high thermal load suffers from thermally induced depolarization [29], which is typically in the range of 25% for a single amplifier [30] and up to 37% for a configuration consisting of twin Nd:YAG amplifiers [31]. To compensate thermal depolarization, we utilize a 90 deg quartz rotator [32] and a 1∶1 relay imaging scheme [33] with twin amplifier modules [31].…”

Research on the mechanism of high power solid laser

“…With the development of solid laser application, there are higher requirements for the output power, beam quality and stability. As one of the most important factors, the thermal lens effect gets more attention in design of resonant cavity [1][2][3][4][5][6][7][8][9].…”

High-resolution confocal fluorescence thermal imaging of tightly pumped microchip Nd:YAG laser ceramics

“…In such systems the presence of focalized pump beams leads to the appearance of relevant thermal gradients. These, in turns, could strongly affect the laser performance of the whole laser system due to a great variety of physical effects such as thermal lensing, thermal birefringence, thermal induced fluorescence quenching and so on [5][6][7]. It should also be pointed out that, in microchip lasers, pump-induced non-homogeneous temperature distributions are not always undesirable as they provide stability to the plane-plane resonator [8,9].…”