The research of red beam generation by frequency-doubling of a Nd-YAG laser

In recent years, with the rapid developments in the technology of diode lasers, diode-pumped all solid state red laser is widely accept as a highly reliable, compact and efficient source for image projection and pumping tunable Cr:LiSAF lasers. Although the different application area needs different laser characteristics, most application field requires high beam quality and high power output, especially in large image projection system. In this paper we focus on how to improve the output power of red beam. What´s more, to avoid two wavelength operation which may cause a problem for frequency doubling and obtaining high output power, we placed a solid etalon into the laser cavity. And the experiment results demonstrate that the proposed method can avoid the damage of the end surface of the KTP and improve the stability of the output power. Finally, we obtain a maximum single end output power of 6.4W operating at a single wavelength of 660nm with an instability about ±1%.