Optimization of a cw mode-locked frequency-doubled Nd:LiYF_4 laser

Abstract

Several drawbacks of a cw-pumped mode-locked Nd:LiYF₄ laser are outlined, and it is shown how to overcome them. For the first time, attention is paid to thermally induced astigmatism and its compensation in a Nd:LiYF₄ rod. An optimized system generates an average output power similar to that of a typical Nd:YAG laser, however, with an increased stability and with pulse durations that are significantly shorter. The higher peak power in Nd:LiYF₄ can result in a higher conversion efficiency in a frequency-doubling process, provided the doubling crystal can handle the high average power. It will be demonstrated that a well-engineered Nd:LiYF₄ system may become the preferred choice for many applications, including seeding regenerative amplifiers and pumping synchronously mode-locked dye laser oscillators and amplifiers.