Yb:YAG power oscillator with high brightness and linear polarization

Abstract

A diode-pumped Yb:YAG laser with a novel end-pumped zigzag slab architecture has been developed. This architecture provides uniform transverse pump profiles, conduction cooling of the laser crystal, mechanical robustness, and ready scalability to higher powers. At room temperature the laser emits 415 W of cw power with 30% optical conversion efficiency. An image-inverting stable resonator permits a high-brightness output of 252 W with linear polarization and an average M(2) beam quality of 1.45. Q-switched pulse energies of as much as 20 mJ and average Q<i/>-switched powers of as much as 150 W were obtained while M(2) was maintained at <1.5.

Cryogenic, high power, near diffraction limited, Yb:YAG slab laser

“…The gain medium chosen is a 1 at. % Yb:YAG zigzag slab, of dimensions 50 x 3 x 2 mm, with undoped YAG end-caps, similar to the design described in [14]. It is held by an all metal clamp, forming the "laser head".…”

A cryogenic, end pumped, zigzag slab laser suitable for power scaling

“…1. It uses a laser crystal design developed for end pumped, single pass, room temperature operation [4]. End pumping is achieved using two fast-axis-collimated 750 W diode stacks, the outputs of which are guided into the slab by lens ducts as shown.…”

Compact, High Brightness and High Repetition Rate Side-Diode-Pumped Yb:YAG Laser

“…Diode-pumped Yb:YAG lasers are a very attractive alternative to the lasers utilizing classical laser material such as Nd:YAG for reducing thermal effects and for scaling the Q-switched output power to the desired level. Yb:YAG has nearly four times less heat generation during lasing than comparable Nd:YAG laser systems [Bibeau et al, 1998, Honea et al, 2000, Rutherford et al, 2001, Goodno et al, 2001 due to a much smaller quantum defect in Yb 3+ . However, there are two shortcomings with Yb:YAG crystals related to a quasi-three-level nature of its laser transition.…”

“…The edge-pumping zigzag slab design eliminates the complexity of the cooling-pumping interface design of the conventional slab lasers, but achieving TEM 00 mode operation of this laser at high levels of pumping meets is also difficult. Another slab laser design is the end-pumped zigzag slab laser architecture [Goodno et al, 2001]. The slab is pumped from each end by laser diode bars using a lens duct.…”