We have performed a basic experiment on a diode laser pumped Tm:Ho:YLF laser with the purpose of developing a light source for a JEM-borne coherent Doppler lidar. This laser oscillator has 8-figure type ring cavity and its cavity length is 2.9m. Unidirectional operation was performed with a Faraday rotator and a polarizer in the cavity. A composite crystal is used for the oscillator. Doped YLF is clad with undoped YLF and had undoped YLF at both ends. The crystal is supported its both ends with copper, and is cooled to a temperature of 205K in a vacuum chamber. Doped part of the crystal is pumped by four diode lasers with total pumping energy of 700mJ. We have obtained Q-switched pulses of 5.OmJ at pulse repetition rate of 10 Hz, with a wavelength of 2.05 micrometer and a pulse width of 326ns, and an optical to optical efficiency of 0.7%. In the injection seeding for a single mode operation, a computer controls cavity lengths by way of moving one of mirrors so that pulse buildup time keeps minimum value. We have also obtained a spectrum width of 1 .5MHz, and this value is almost same as Fourier transform limited width.

Date Published: 13 February 2001
PDF: 8 pages
Proc. SPIE 4153, Lidar Remote Sensing for Industry and Environment Monitoring, (13 February 2001); doi: 10.1117/12.417079

Published in SPIE Proceedings Vol. 4153:
Lidar Remote Sensing for Industry and Environment Monitoring
Upendra N. Singh; Upendra N. Singh; Kazuhiro Asai; Toshikasu Itabe; Toshihiro Ogawa; Nobuo Sugimoto, Editor(s)