Laser performance study of mixed vanadate crystals <inline-formula><math display="inline" overflow="scroll"><mrow><mi mathvariant="normal">Nd</mi><mo>:</mo><msub><mi mathvariant="normal">Y</mi><mi>x</mi></msub><msub><mi mathvariant="normal">Gd</mi><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub><mi mathvariant="normal">V</mi><msub><mi mathvariant="normal">O</mi><mn>4</mn></msub></mrow></math></inline-formula> with direct and indirect pumping

Abstract

We present, for the first time, comparative studies of laser performance in the mixed vanadate crystals Nd:YxGd1−xVO4 with direct and indirect pumping. A series of mixed vanadate crystals Nd:YxGd1−xVO4 with different yttrium and gadolinium composition ratios but the same Nd3+ dopant level is prepared under the same fabrication processes and their laser performance in the TEM00 mode operation is studied using the same experimental configuration under direct pumping with laser diodes at 880 nm as well as indirect pumping at 808 nm. Remarkable improvement in laser efficiency and maximum achievable output power is achieved under direct 880-nm excitation over indirect 808-nm excitation. The maximum optical slope efficiency in the TEM00 mode operation is 74% with direct 880-nm pumping, which also produces the maximum overall optical-to-optical conversion efficiency of 59%. The maximum attainable laser power is up to 50% higher under direct 880-nm pumping over the more conventional 808-nm pumping. These achieved results provide valuable insight into crystal composition selection and pump schemes for the mixed vanadate crystals, which have the potential to tailor laser parameters through crystal composition engineering.