CW room temperature upconversion lasing at blue, green and red wavelengths in infrared-pumped Pr(3+)-doped fluoride fibre

Continuous-wave, room temperature laser oscillation at 491 nm, 520 nm, 605 nm and 635 nm in a Pr(3+)-doped fluorozirconate fiber pumped simultaneously at 1.01 micron and 0.835 micron is reported. An output power of 185 mW has been measured for the 635 nm transition. The thresholds obtained suggest that laser diode-pumped operation of all four transitions should be possible in an optimized fiber.