Holmium YLF amplifier performance and the prospects for multi-Joule energies using diode-laser pumping

Author

Storm, Mark E.

Author_Institution

Hughs/STX, Hampton, VA, USA

Volume

29

Issue

2

fYear

1993

fDate

2/1/1993 12:00:00 AM

Firstpage

440

Lastpage

451

Abstract

Laser studies that examined the amplifier characteristics of holmium-doped yttrium lithium fluoride (YLF) at 300 K are discussed. An inversion ratio n⁵I₇/n _Ho of 0.37 was reached, resulting in a measured small-signal gain coefficient of 0.50 cm^-1. In a flashlamp pumping experiment, an output energy of 240 mJ was achieved for 38.5 mJ of input energy, resulting in a large gain of 6.2. An amplifier model developed for diode laser pumping was adapted to consider this flashlamp-pumped case. The agreement between the theory and the experiment is good. Multipass amplifier calculations using the model suggest that the Ho:Tm:YLF laser crystal can support a 12% electrical to optical efficiency at 300 K, even in the presence of upconversion

Keywords

holmium; laser theory; lithium compounds; optical pumping; population inversion; solid lasers; yttrium compounds; 240 mJ; 300 K; 38.5 mJ; Ho:YLF amplifier performance; LiYF₄:Ho; LiYF₄:Ho,Tm; diode-laser pumping; electrical to optical efficiency; flashlamp pumping; inversion ratio; multi-Joule energies; multipass amplifier; output energy; small-signal gain coefficient; upconversion; Diode lasers; Gain measurement; Laser excitation; Laser modes; Laser theory; Lithium compounds; Optical amplifiers; Pump lasers; Semiconductor optical amplifiers; Stimulated emission;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.199299

Filename

199299