A.C. Large

Growth and low-threshold laser oscillation of an epitaxially grown Nd:YAG waveguide

We report 1.064-microm laser operation of an epitaxially grown Nd: YAG planar waveguide with thresholds as low as ~0.7 mW when high-reflectivity mirrors are used. The output is single mode and, when a 83% reflectivity output coupler is used, has a diode pumped slope efficiency of ~40%. Output powers in excess of 60 mW have been obtained when pumping with a Rhodamine 6G dye laser.

High slope efficiency and low threshold in a diode-pumped epitaxially grown Yb:YAG waveguide laser

We report the 1.03µm and 1.05µm laser operation of a diode-pumped Yb-doped YAG planar waveguide. The fabrication and characterisation of such multilayer planar waveguides by liquid phase epitaxy are also described. Diode-pumped laser results (77% slope efficiency) obtained with 2.1% output coupling compare very favourably with results reported elsewhere for bulk lasers.

Ion-implanted Nd:GGG channel waveguide laser

We report what is to our knowledge the first fabrication and laser operation of ion-implanted Nd:GGG channel waveguides. Diode-pumped operation has been achieved with absorbed power thresholds as low as ~2 mW and a slope efficiency of ~30% with respect to absorbed power.

Channel waveguide laser at 1 μm in Yb-indiffused LiNbO 3

We report laser action in a Ti-diffused LiNbO3 waveguide doped with trivalent Yb ions by thermal indiffusion. Lasing was observed at 1008, 1030, and 1060 nm with thresholds as low as 15-mW launched pump power. We reduced photorefractivity, which initially permitted only intermittent lasing, by annealing the sample in wet O2. The annealed sample lased continuously in a cavity formed by high-reflectivity mirrors; however, with a 7% output coupler the output power exhibited instabilities. The greatest value of the output power observed under these conditions was consistent with a slope efficiency of ~16% with respect to absorbed power.

Low threshold quasi‐three‐level 946 nm laser operation of an epitaxially grown Nd:Y3Al5O12 waveguide

We report the 946 nm laser operation of an epitaxially grown Nd:YAG planar waveguide. The incident and absorbed power thresholds of 4 and 1.2 mW, respectively, are lower than those reported for bulk lasers when using a similar experimental setup. We also report the use of Ga doping of the active layer to increase the refractive index difference to allow the production of very small guiding layers.

Optical absorption and luminescence of Tm3+-doped LiNbO3 and LiNbO3 (MgO) crystals

The optical properties (absorption, luminescence and lifetime) of Tm3+-doped LiNbO3 and LiNbO3(MgO) have been measured. It has been found that the 1D2, 1G4, 3H4 and 3F4 levels decay radiatively having temperature-independent lifetimes. These results are compared with the radiative transition rates calculated by using the Judd-Ofelt theory. It has also been found that MgO-codoping affects very slightly the optical properties of Tm3+ ions, except for a general broadening of the spectra. Oscillator strenghts and Judd-Ofelt parameters are not affected by MgO codoping.

Quasi-three level 1.03 μm laser operation of a planar ion-implanted Yb:YAG waveguide

Abstract The first laser operation of an Yb:YAG waveguide is reported. Room temperature, continuous wave operation was achieved at a threshold of 30 mW. Projected thresholds of a few milliwatts for a channel waveguide indicate that for quasi-three level lasers, a waveguide configuration, even if lossy, can be highly beneficial.

An efficient, diode-pumped, ion-implanted Nd: GGG planar waveguide laser

We report the first laser operation of an ion-implanted Nd:GGG planar waveguide laser at 1.062µm. Diode array and dye-laser pumping is described with threshold absorbed powers as low as 8mW. Slope efficiencies of 30% with respect to absorbed power have been observed with output powers of up to 40mW.

A side-pumped Nd:YAG epitaxial waveguide laser

We report the first operation of a side-pumped crystal waveguide laser. Both diode array and dye laser side-pumping of an epitaxially grown Nd:YAG planar waveguide laser have been demonstrated, with thresholds as low as 8 mW observed for a simple plane mirror cavity. Output slope efficiencies of 19% have also been demonstrated. The threshold and slope efficiency of this system is found to be in good agreement with a simple analytical model.

Optically written waveguides in ion implanted Bi4Ge3O12

We report the first observation of optically written channel waveguides in ion implanted Bi4Ge3O12 (BGO). Raman spectroscopy has been used to investigate the changes occurring due to both the original ion implantation and the subsequent optical writing of channel waveguides