In this paper an optically pumped tunable ring-laser system based on low-loss integrated optic titanium doped sapphirelike waveguides on silicon is presented including simulation results and a characterisation of the realised system. The Al₂O₃ thin film layers are doped in situ with titanium in a PECVD deposition from metal-organic precursors. The waveguides are patterned by reactive ion etching (RIE) to obtain high quality, low-loss waveguides. Afterwards the wafer is annealed by RTP (Rapid Thermal Processing). Thereby the layers change to a sapphire-like morphology and the titanium becomes optically activated without the formation of larger crystallites so that higher losses due to scattering are prevented. For tuning the laser, two solutions are presented. The first is a ZnO based electro-optically tunable etalon which is integrated in the active ring; the second is an also ZnO based coupled ring resonator which can be tuned either by the electro-optical effect or elasto-optically by placing it on a membrane. The required directional element that ensures the propagation in only one direction of the ring is realised by a new "ratch-reel structure" which acts as an optical diode. As the optical field is shifted to the outer periphery of the ring, it is possible to realise a structure that scatters the optical field in one propagation direction, whereas in the other direction it propagates with low loss. The system is pumped by a frequency doubled Nd-YAG-laser at 532 nm which is coupled to the ring via a SiON waveguide. The output power is coupled to a tangential waveguide where the coupling coefficient is determined by distance and refractive indices.

Date Published: 17 April 2006
PDF: 7 pages
Proc. SPIE 6190, Solid State Lasers and Amplifiers II, 619006 (17 April 2006); doi: 10.1117/12.664034

Published in SPIE Proceedings Vol. 6190:
Solid State Lasers and Amplifiers II
Alphan Sennaroglu, Editor(s)