Nd:YAG single‐crystal fiber laser: Room‐temperature cw operation using a single LED as an end pump

cw laser action has been obtained using as‐grown single‐crystal Nd:YAG fibers end‐pumped by a single high‐radiance LED. The fibers were 0.5 cm long and 80 μm in diameter, and the diameter of the LED luminous area was 85 μm. The lowest cw laser threshold was observed at a diode drive current of 45 mA.