Monochromatic end-pumped operation of an alexandrite laser

Tapered diode-pumped continuous-wave alexandrite laser

“…The alexandrite laser output power was less than 1 mW [51]. The same group has then pumped alexandrite lasers using two 250 mW multimode diodes around 640 nm and obtained 25 mW of cw output power [36]. In a study published in 2005, using a high-power (10 W) diode array consisting of many single-emitter multimode diodes around 680 nm, cw output powers as high as 1.3 W have been obtained from alexandrite lasers [52].…”

“…It has many superior optical and thermal properties (see Table 1), including an intrinsic slope efficiency of 65% [36], a broad tuning range from 700 to 860 nm [24,33], lack of concentration quenching of fluorescence lifetime [31], and, interestingly, increased laser performance at elevated temperatures above room temperature [33]. Due to all of these, alexandrite was one of the most popular tunable lasers on the market during the 1980s [31].…”

“…Maximum reported slope efficiencies are 1.5% (optical-tooptical with respect to incident pump power) [25,46]. On the other hand, single transverse-mode pump sources like dye lasers or argon ion lasers resulted in more efficient laser operation (up to 64%) [36,47]. However, for these cases the pump source itself is an expensive laser system.…”

“…Diverse excitation bands (broadband 4 T 1∕2 excitations and narrowband R 1∕2 excitations) allow different pump options for alexandrite. Flashlamps [45], Xe/Hg arc lamps [25,46], krypton ion lasers (647 nm) [47], dye lasers (615-680 nm) [36], frequencydoubled neodymium lasers around 530 nm [48,49], and even sunlight [50] have been used for pumping cw alexandrite lasers. With lamp pumping, output powers as high as 60 W could be obtained.…”

High efficiency CW green-pumped alexandrite lasers

“…The first report of a diode-pumped Alexandrite laser [3] compared the output achievable by pumping with a high-brightness, near diffraction limited dye laser operating at 645 nm with that obtainable using either a single or two red diode pumps operating at 640 and 644 nm. This approach took advantage of the broad 600 nm absorption peak of the alexandrite laser material.…”