波长可调谐的瓦级连续橙红光激光器

Watt-level continuous wave orange-red laser with wavelength tunable

介绍了基于复合腔结构的全固态波长可调谐的连续橙红色激光的输出特性。该复合腔由一个使用周期极化晶体MgO∶PPLN的信号光单谐振光参量振荡器和一个LD侧面泵浦Nd∶GdVO_4晶体的1 062.9nm基频光谐振腔构成。s-偏振1 062.9nm泵浦光抽运单谐振光参量振荡器产生s-偏振信号光腔内独立振荡。通过复合腔结构的优化设计,使独立振荡的p-偏振1 062.9nm基频光与s-偏振信号光在2个子腔的重叠区内通过II类角度匹配KTP晶体的腔内和频过程获得橙红色激光。当MgO∶PPLN晶体的调谐温度从30℃上升至200℃时,s-偏振信号光的中心波长产生红移,导致其与p-偏振1 062.9nm基频光和频产生的橙红色激光的中心波长从620.2nm红移至628.9nm。同时测得中红外波段闲频光的中心波长从3 714.2nm蓝移至3 438.3nm。在30℃最低设定温度时,中心波长620.2nm的橙红色激光和中心波长3 714.2nm的闲频光最大连续输出功率分别达到2.0 W和2.9 W。

Output characteristics of continuous wave（CW）orange-red laser with all-solid wavelength tunable based on composite cavity structure are introduced. Composite cavity is composed of an s-polarized signal singly resonant optical parametric oscillator （SRO） using an MgO-doped periodically-poled LiNbO3 （MgO： PPLN） crystal and a p-polarized 1 062.9 nm fundamental frequency light cavity. Independent oscillations of signal light pumped by an s-polarized 1 062.9 nm laser and p-polarized 1062.9 nm fundamental frequency are generated in respective cavity, which produces orange-red laser using a type-II critical phase-matched KTP crystal in intracavity sum-frequency generation process. When tuning temperature of MgO∶PPLN crystal rises from 30℃ to 200℃, CW orange-red laser beams are obtained with tunable wavelengths from 620.2 nm to 628.9 nm based on wavelength red-shift of s-polarized signal light, corresponding to a measured waveband of mid-infrared idler light from 3 714.2 nm to 3 438.3 nm. At minimum temperature of 30℃, maximum CW output power of orange-red laser is obtained to be 2.0 W at 620.2 nm, corresponding to CW output power of idler light is 2.9 W at 3 714.2 nm.