Laser operation of a low loss (0.1 dB/cm) Nd:Gd_(3)Ga_(5)O_(12) thick (40 μm) planar waveguide grown by pulsed laser deposition

摘要

Waveguiding films of Nd:Gd_(3)Ga_(5)O_(12) with a thickness up to 40 m have been fabricated by pulsed-laser deposition on Y_(3)Al_(5)O_(12) (100) substrates. A laser threshold of 18 mW of absorbed pump power has been obtained and lasing action has been observed at 1060.6 nm for pump powers close to the lasing threshold, and at both 1059.0 and 1060.6 nm at pump power levels of approximately 1.5 times above threshold. Waveguide propagation losses of 0.1 dB/cm have been obtained by measuring the absorbed pump power threshold for laser operation at 1060.6 nm for a range of output couplers with various reflectivities. Slope efficiencies of 12.3% and 17.5% were derived using output couplers with a transmission of 2.2% and 4.5%, respectively. The combination of low propagation losses and high numerical aperture for the waveguides indicates the potential of the fabrication technique to produce high quality thick multi-layer waveguides. Such designs are suitable for the development of high-power diode-pumped laser sources of near-diffraction-limited beam quality.