Low-current-density LED-pumped Nd: YAG laser using a solid cylindrical reflector

Abstract

Results of a development program for light-emitting-diode (LED)-pumped neodymium-doped yttrium aluminum garnet (Nd: YAG) lasers highlight a significant design feature: an index-matching method to increase the coupling efficiency of the laser. A solid-glass half-cylinder measuring 5.0×5.6 cm was used for index matching and also as a pumping cavity reflector. An array of twenty 0.034×0.254-cm GaAlAs diodes, connected in series, aligned such that the emission area formed a straight line, was used to excite a 1.5×56-mm laser rod. The interfaces between the diode array, glass half-cylinder, and laser rod were filled with viscous fluid of refractive index n = 1.55. Experiments performed with both the glass half-cylinder and a gold-coated stainless steel reflector under the same operating conditions indicated that the index-matching half-cylinder gave 160–200% improvement of coupling efficiency over the metal reflector at various operating temperatures. For a 207-A/cm2 driving current density the laser produced cw output power of 27 mW.

LED side-pumped Nd3+:YVO4laser at room temperature

“…In the 1970s, different works on neodymium lasers (such as Nd:YAG or Ndpentaphosphate) were published with LED as the pump source [3][4][5][6][7][8] . Laser effect was also demonstrated with an LED pumped Yb:YAG crystal 9 .…”

High Stability LED-Pumped Nd:YVO4 Laser with a Cr:YAG for Passive Q-Switching

“…An LED pumping laser was first verified in a Dy:CaF 2 crystal in 1964 [4]. In the 1970s, several types of LED-pumped neodymium lasers (such as Nd 3+ doped crystals) were developed [5][6][7][8][9]. In these early years, the reported LED-pumped lasers were typically cooled by water or more complex structures.…”

Monolithic Light Reflector‐Nanowire Light Emitting Diodes

“…[7,10] A typical method of improving light extraction of LEDs is to mount the reflectors on the outside of the device chips. [11][12][13] However, this approach not only requires a high fabrication cost but also has limited to the applications for ultracompact nanoscale devices. Therefore, it is important to realize ultrasmall chips or pixels for the future micro-/nanodisplay applications.…”