Birefringence compensation in single solid-state rods

Abstract

Various methods for compensating birefringence depolarization in solid-state rods are theoretically and experimentally analyzed and compared. Gaussian and flat top beam profiles are investigated. The efficiency in depolarization loss reduction using different techniques is discussed in terms of beam profile, rod fill factor, and thermal heat load. In Nd:yttrium-aluminum-garnet, the depolarization loss can be efficiently reduced below 5% with a compensating quarter-waveplate, up to 20 W heat load for a flat top beam and up to 70 W for a gaussian beam.

High-power, Joule-class, temporally shaped multi-pass ring laser amplifier with two Nd:glass laser heads

“…The thermal depolarization induced by the wasted heat deposited in the laser rods significantly deteriorates the beam quality. There are two main conventional types of thermal depolarization compensation methods in high-power laser systems [17, 19] . Methods in the first category are used in one-laser-head systems that comprise a FR or a QWP and a high-reflectivity mirror; methods in the other category are used in two-identical-laser-head systems with a quartz rotator combined with an image relay system, which causes the polarization rotation between the two laser heads.…”

Thermal effects and their mitigation in end-pumped solid-state lasers

“…With the quarter-wave plate present and aligned with its fast or slow axis parallel to the polarization direction defined by the polarizer, then the spatially-dependent depolarization loss is modified according to the expression [34,35]…”

Laser and optical transport line for laser-based ion beam diagnostics and control in the SNS linear accelerator

“…1(b). The optics between the YAG rod and reflector contains a Faraday rotator and a pair of relay lenses to avoid thermal-induced birefringence inside the gain medium [2,3].…”