Abstract
We demonstrated Nd:YAG and Nd:YVO4 laser pumped by light emission diodes (LEDs) at 750 and 810 nm. In the 750-nm LED with a 1% output coupling from a linear cavity containing a 2-cm long Nd:YAG crystal, the laser generated 37.5 J pulse energy at 1064 nm with M2 = 1.1 when pumped by 2.73-mJ LED energy in a 1-ms pulse at a 10 Hz rate. The measured optical and slope efficiencies for this linear-cavity laser were 1.36%, and 9%, respectively. With 1% and 5% output couplings from a Z-cavity containing the same laser crystal, the lasers generated 346 J and 288 J pulse energy with optical efficiencies of 3.4% and 2.8% and slope efficiencies of 6.6% and 14%, respectively, for the same 1-ms pump pulse repeating at a 10 Hz rate. At the highest output from the Z-cavity, the measured M2 for the beam was 3.6. And that, in 810-nm LED, with 1% output coupling from a linear cavity containing a 2-cm long Nd:YAG crystal, the laser generated 172.3 J pulse energy at 1064 nm with TEM00 when pumped by 12.26-mJ LED energy in a 1-ms pulse at a 10 Hz rate. The measured optical and slope efficiencies for this linear-cavity laser were 1.4% and 2%. Compared with a 805-nm laser diode pumped Nd:YAG, we have realized 830 mw at 1064 nm for an input pump power of 5.6 W at 805 nm with cw mode. Also, we have obtained 0.74 mJ at 1064 nm for an input pump power of 4.8 mJ at 805 nm with qcw mode. The slope efficiencies of the cw and qcw mode were 17.9% and 16.1%, respectively. There was an 11% laser output power difference between the 4oC temperature difference.