Thermally induced window birefringence in high-power copper vapor laser

Autor: G. Miron, Haim Lotem, Mordechai Lando, Shlomo Eisenbach, Zvi Horvitz, Shimon Gabay
Rok vydání: 1993
Předmět:
Zdroj: 8th Meeting on Optical Engineering in Israel: Optoelectronics and Applications in Industry and Medicine.
ISSN: 0277-786X
DOI: 10.1117/12.151094
Popis: We have used a copper vapor laser amplifier of 80 mm tube diameter to amplify a 10 watt laser beam to a 100 watt level. The output beam was found to be elliptically polarized, and the eccentricity and the direction varied over the beam cross-section. Assuming that the polarization changed due to the temperature gradient in the laser amplifier windows, we have compared spatially resolved calculations to spatially averaged measurements. Our calculations show that the described behavior stems from the high tube temperature of the copper vapor laser which may exceed 1600 degree(s)C. As a result, the windows were heated by IR radiation, causing a cylindrically symmetric temperature distribution. The temperature gradient causes a mechanical stress, and a circularly symmetric birefringence. Acting on the vertical polarization, this birefringence leads to the spatially dependent depolarization. We have analyzed the average polarization and studied two ways to increase it. The vertical to horizontal ratio was about 4:1 for 12 mm windows, 9:1 for 6 mm windows and 19:1 for 6 mm shaded windows. The experimental results were in good agreement with the calculations.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Databáze: OpenAIRE