With output powers of 12, 15, and 18 Watts, Coherent says its new Verdi G series of 532nm scientific grade lasers offer many advantages over earlier lower-power models.
Despite their higher output, the new Verdi G12, Verdi G15, and Verdi G18 lasers are actually contained within smaller laser heads measuring just 68 x 98 x 214mm – just 40% of the volume of earlier models. The lasers output a vertically polarised beam with a M² of less than 1.1 and very low total noise – just 0.02% measured over the frequency range from 10Hz to 100MHz, according to Coherent.
This low noise is attributed to the reduced upper state lifetime of the gain medium in these optically pumped semiconductor lasers (OPSL), which is said to eliminates the ‘green noise’ that often compromises performance of 532nm solid state lasers. This, and advanced surface cooling, means that there are no thermal lensing issues with these devices and consequently they can be operated at anywhere from 10 to 100% of their rated output with no effect on beam parameters, says Coherent.
The lasers are intended primarily for pumping titanium : sapphire (Ti:S) oscillators, where their power will enable tunable, mode-locked output of more than 4 Watts (the G15 and G18 can pump a Ti:S and a regenerative amplifier at the same time).