Half-Watt single frequency yellow 561 nm and yellow-green 553 nm DPSS lasers with record 19% optical conversion efficiency

Abstract

Since the first introduction of DPSS lasers at 561 nm in 2004, the power level required by some biotechnical applications has always increased. Oxxius has contributed to fulfill the demand thanks to the introduction of the SLIM-561 100mW in 2008 and of the SLIM-561 200mW and 300mW in 2009. More recently, new dyes or nano-dots have required shorter wavelengths (such as 553 nm) and new applications such as Laser Doppler Velocimetry requiring both high power and single frequency operation have appeared.In this presentation, we demonstrate how to further increase the power. 553nm and 561 nm emission are obtained by frequency doubling the 1106 nm and 1123 nm lines of Nd:YAG. The latter transitions are significantly weaker than the 1064 nm line. As a consequence, any loss in the cavity significantly increases the laser threshold. Because of the perfect alignment of the crystal interfaces and the low divergence of the intracavity beam, monolithic cavities demonstrate significantly reduced round-trip losses compared to standard cavities. Consequently, laser threshold can be dramatically reduced and the nonlinear loss, responsible for the visible emission, can easily dominate the linear losses. We have taken standard monolithic cavities of our commercial SLIM-561 products and have increased the pumping power up to 2.8 W. Yellow and Yellow-green powers have not shown any sign of saturation and 0.5 W could be achieved at both wavelengths. This results in a record 18% pump to signal optical efficiency. We have checked that the emission remained single frequency whatever the pumping power.

Low noise Raman lasers for yellow-orange spectrum coverage

“…The Raman cavity is made of a 2 mm long Nd:YAG and a 5 mm long KTP crystals of a 561 nm laser [2]. Both crystals have a broadband (1100-1250 nm) HR mirror on one side and no coating on the other side.…”

“…Two families of such lasers are now well in the market. In the first family, the amplifier is a Nd:YAG or a Nd:YVO 4 crystal and available wavelengths are 532 nm, 543 nm, 553 nm [2] and 561 nm. In the second family, the amplifier is an optically pumped semiconductor (OPS) and available wavelengths are 532 nm, 561 nm, 568 nm and 577 nm [3].…”

All-Solid-State Efficient CW Yellow Laser under Direct Diode-Pumping

“…Yao et al presented a 561 nm laser with 1.2 W cw output power by intracavity frequency doubling of a diode-end-pumped Nd:YAG laser with a 808 nm LD and a LBO crystal, resulting in an optical to optical efficiency (η o-o ) of 13.3% and M 2~1 .67 [8]. Georges et al demonstrated a diode-end-pumped single frequency 561 nm laser with an 808 nm LD and a KTP crystal, giving a 0.5 W cw yellow output with η o-o~1 8% and M 2~1 .1 [9]. As high as 60 W of 561 nm laser average output was acquired by acousto-optical Q-switching and intracavity frequency doubling in an 808 nm diode-side-pump structure, with η o-o~6 .1% and M 2~3 0 [10].…”

Demonstration of miniaturized 20mW CW 280nm and 266nm solid-state UV laser sources

“…Monolithic laser cavity architectures are well known to fulfill this need 4 . The monolithic cavity of the visible laser is displayed on figure 1 5,6 . It is made of 4 crystals: a 2.5 mm long amplifier (Nd:YAG), quartz waveplate, silica based polarizer and a 5 mm long nonlinear crystal (KTP).…”