Two twin AgGaSe2 crystals (lc=20 mm) cut for the second-harmonic generation (SHG) of 10.2 μm radiation have been submitted to up to 1.3 W single-mode continuous-wave (CW) output of a CO2 laser focused to a decreasing beam radius w0. For a power density exceeding 1.6 kW/cm2, corresponding to a focusing parameter l= lc zR far under the theoretical optimum one, the second-harmonic (SH) generated power starts to saturate due to thermal effects. The study of the conversion efficiency versus the focusing parameter for the walkoff-compensated twin device reveals that this two-crystal device is more efficient than would be a single crystal of length 2lc, despite the small walkoff angle in this material.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering