| Abstract [eng] |
Because the wavelength of laser radiation is very difficult to change and is usually fixed, in practice certain devices called parametric light generators and amplifiers, which allow the wavelengths to be evenly change over a wide spectrum. These devices can be used in spectroscopy, biophotonics, detection of various chemicals, nonlinear microscopy, gas or laser range detection, biophotonics, biomedicine and in other areas. Quite a number of parametric light amplifiers and generators have been developed these days in the range of long pulse durations (more than 1 ns), ultrashort (less than 100 ps) pulse durations, however subnanosecond pulse (less than 1 ns and more than 100 ps) generators only few have been invented. The purpose of this work was to construct and investigate combined and optimized optical parametric amplifier system and used generated signal wave and second-harmonic generation in signal wave in MgO:PPLN OPG as a seed. In this work the spectral, energy and temporal characteristics of OPA were measured. The difference frequency wave (signal wave) tuning range was 426 – 475 nm in range 1, and in range 3 was 532 – 710 nm, which was limited by the tuning limits of the seed radiation spectrum (1400 – 2150 nm and 700 – 1064 nm). The maximum signal power in range 1 at 475 nm was 27 mW and the overall conversion efficiency at 475 nm obtained 42,1%, in range 3 the maximum signal power was 0,91 mW, efficiency 2,1% at 689 nm. In range 1 saturation mode of LBO OPA operation was achieved with a pump power of 85 mW, which indicates that the device is optimized. Furthermore, numerical simulations displayed qualitatively similar results to the experimental results. |
