Semiconductor Absorber Mirror Research Articles

Cost Effective Profiling of Neodymium-Doped Vanadate Laser Pulses

As environmental conditions and component degradation and failure are known to affect the performance of ultrafast lasers, it is important to monitor their state in any nonlinear optical study. This may be achieved by measuring the temporal width of the laser pulses using an autocorrelator. In this work, an autocorrelator for measuring the pulsewidth of mode-locked lasers was custom-built using pieces of equipment usually found in a typical ultrafast optics laboratory. The assembled equipment was tested using SESAM (Saturable Semiconductor Absorber Mirror) mode-locked neodymium-doped vanadate (Nd:YVO4) laser having manufacturer specified average output power of 1.6 W and 10 ps pulsewidth. Using the background-free autocorrelation technique, the pulse width of the laser was measured to be 10.4 ps. This type of autocorrelator is cost effective and may be handy in situations where research funds are limited; a scenario commonly experienced in research laboratories of developing countries. Additionally, the processes involved in assembling the autocorrelator provide a useful learning experience for new researchers. The study also outlined the processes involved in modifying an existing autocorrelation setup in order to measure laser beam spot size; a useful parameter in nonlinear optical studies.

High average power and short pulse duration continuous wave mode-locked Nd:GdVO4 laser with a semiconductor absorber mirror

Passive mode locking of a solid-state Nd:GdVO4 laser is demonstrated. The laser is mode locked by use of a semiconductor absorber mirror (SAM). A low Nd3+ doped Nd:GdVO4 crystal is used to mitigate the thermal lens effect of the laser crystal at a high pump power. The maximum average output power is up to 6.5 W, and the pulse duration is as short as 6.2 ps. The optic-to-optic conversion efficiency is 32.5% and the repetition rate is about 110 MHz.

High-average-power and high-conversion-efficiency continuous wave mode-locked Nd:YVO 4 laser with a semiconductor absorber mirror

A high-power continuous wave (cw) mode-locked Nd:YVO 4 solid-state laser was demonstrated by use of a semiconductor absorber mirror (SAM). The maximum average output power was 8.1 W and the optic-to-optic conversion efficiency was about 41%. At the maximum incident pump power, the pulse width was about 8.6 ps and the repetition rate was 130 MHz. Experimental results indicated that this absorber was suitable for high power mode-locked solid-state lasers.