LED side-pumped Nd³⁺:YVO₄laser at room temperature

Abstract

The lighting market has recently improved LED performance by orders of magnitudes. In parallel, massive production decreases dramatically LED price. Those improvements triggered new interests for LED pumping of lasers which was first studied in the early 1980s on neodymium doped and ytterbium doped lasers at low temperature. Since the 2000's, several research teams started to revisit the concept of LED pumped lasers: polymer laser, fiber laser and semiconductors have recently demonstrated laser effect under visible LED pumping. However, no experimental results were reported on LED pumped bulk crystals. In this paper, we demonstrated for the first time a LED pumped Nd:YVO4 laser operating at room temperature. We investigated two pumping wavelengths: in the amber around 600 nm and in the near infrared around 850 nm. The laser operated in quasi-cw-pumping regime to increase the LED intensity. We performed a two-mirror cavity transversely pumped by 36 LEDs. Laser operation was achieved at room temperature for the both pump wavelengths: a maximum output energy of 40µJ for an emitted energy of 7.4 mJ with infrared pumping and an energy of 11.7 µJ for an emitted energy or 2.3 mJ with amber pumping.This works demonstrated that LED pumping has an interesting potential to realize ultra-low-cost solid-state lasers operating in pulsed regime at kHz repetition rate and with energies in the mJ range.