High beam quality visible laser emission can be directly generated using optically pumped rare-earth (RE) ion doped praseodymium (Pr3+) in a suitable low phonon energy host. Trivalent Pr3+ can generate laser emission in the red, orange, green and blue spectral domains [1]. Direct generation in a RE ion has the advantage of energy storage and broad gain-bandwidths thus allowing tunable, Q-switched, and mode-locked laser operation [2]. Previously we have reported waveguide-based ZBLAN chip lasers in the near IR to mid-IR spectral domain. These chip lasers are based on the ultra-fast laser inscription (ULI) of depressed cladding waveguides into bulk RE ion doped ZBLAN chips.
We report here visible continuous wave laser emission at 636 nm from a praseodymium doped fluorozirconate glass guided-wave chip laser. This ultra-fast laser inscribed gain chip is demonstrated to be a compact and integrated laser module. The laser module, pumped by two polarisation-coupled 442 nm single-mode GaN laser diodes, generates >8 mW lasing output with a beam quality of M2xy~ 1.15 and 1.1 (±0.1). To the best of our knowledge, this is the first visible laser emission from a glass-based waveguide chip laser.
Improved laser performance may also realize laser operation of the lower gain 527 nm green transition, thus allowing the chip laser to simultaneously emit blue (un-depleted pump), green and red laser emission from the same waveguide.
1. T. Sandrock, et al.," Applied Physics B 58, 149-151 (1994).
2. M. Gaponenko, et al., Opt Lett 39, 6939-6941 (2014).
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