Diode pumped laser and doubling to obtain blue light

摘要

A source of coherent blue light comprises a diode laser for pumping a Nd3+ doped member of lasant material disposed within an optical resonator for exciting the 4F3/2-4I9/2 laser transition of a wavelength within the range of 0.870 to 0.960 mu m. The laser radiation within the optical resonator is doubled by means of a doubler crystal of a non-linear, electro-optic material to produce blue light which is then extracted from the optical resonator as an output beam. A thermo-electric cooler is coupled in heat-exchanging relation with the Nd3+ doped laser material to improve the efficiency and the doubler crystal is temperature controlled for phase matching to the laser radiation within the range of 0.870 to 0.960 mu m. The diode pump laser is preferably either a GaAlAs or GaAs diode laser producing pumping radiation of a wavelength of approximately 0.810 mu m. In the case of Nd:YAG end pumped laser material, the laser material is preferably doped to have a high an absorption coefficient as possible and its length is chosen to be within the range of 0.5 to 3 mm. In one embodiment, the lasant material and the non-linear, electro-optic material are disposed in separate optical resonators with the laser resonator optically decoupled from the doubler resonator for inhibiting reflection of optical power back to the laser resonator.