TY - JOUR T1 - Numerical investigation on thin disk laser with unstable resonator TT - بررسی تشدیدگرهای ناپایدار در لیزر دیسک نازک به روش عددی JF - opsi JO - opsi VL - 21 IS - 0 UR - http://opsi.ir/article-1-550-en.html Y1 - 2015 SP - 197 EP - 200 KW - Disk laser KW - Unstable resonator KW - Thermal lensing N2 - In this paper a disk laser with confocal unstable resonator is studied numerically. Using Collins integral and diffraction theory, the calculations are conducted for a positive branch confocal unstable resonator. The active medium of the laser is disk shape and thermal lensing effect is considered in calculations. Laser beam profile and output power is calculated in this paper. Results shows that using very thin disk (about 200 micrometer) is impossible due to high magnitude of losses in unstable resonator. The calculations also shows instabilities in output power for lower than maximum pumping power. M3 ER -