LD pumped high efficiency, high power Tm:YLF laser with adhesive-free bond laser composites

Abstract

Adhesive-free bonded (AFB®) un-doped end-capped and segmentally bonded Tm:YLF laser composites have been investigated for high efficiency LD-pumped laser operations. With a fiber coupled 792-nm diode laser as pump source and a single-end pump arrangement, an optical-to-optical laser efficiency of 48.3% (quantum efficiency of 116%) and a slope efficiency of 55% (quantum efficiency of 132%) have been measured at the laser output wavelength of 1.908 μm. A maximum laser output power up to 29 W has been also achieved before the thermal stress fracture limit. The high laser efficiencies and output power can be attributed to the two-for-one cross-relaxation process and the efficient thermal management of the AFB laser composites.