Gallium-diffused waveguides in sapphire

Abstract

The fabrication and characterization of gallium-diffused planar waveguides in sapphire are reported. Waveguides were fabricated by diffusion of 60-200-nm-thick films of gallium oxide into c -cut sapphire at 1600 degrees C for times ranging from 6 to 16 h. Near-field intensity profiles of the guided modes were measured at wavelengths from 488 to 850 nm, and the surface-index elevation was estimated to be up to (0.6+/-0.02)x10(-2) . Potential applications for low-threshold Ti:sapphire waveguide lasers and for optical integrated circuits with passive and active elements in sapphire are discussed.

Femtosecond-irradiation-induced refractive-index changes and channel waveguiding in bulk Ti3+:Sapphire

“…5 Surface channel waveguides in hard crystalline materials, such as sapphire and Ti 3+ : Sapphire, have been obtained by a number of methods that require the use of photolithographic masks, such as reactive ion etching 6 of planar waveguides, ion indiffusion, 7 as well as in-depth channel waveguides by proton implantation. 8 Here, we report writing of waveguides by femtosecond pulses in a hard crystalline material, Ti 3+ : Sapphire.…”

Thermal stability of microstructural and optical modifications induced in sapphire by ultrafast laser filamentation

“…23 Based on these refractive index changes induced in the surroundings of focal volume and by translation of the sample during irradiation, channel buried waveguides have been fabricated with a great relevance as potential integrated laser sources and high temperature optical sensors. [24][25][26] Nevertheless, and despite its interest from both fundamental and applied point of views, the time and thermal stability of the microstructural changes induced in the sapphire network ͑i.e., stability of the fabricated waveguides͒ after ultrafast laser inscription are still unexplored. This information is of relevance since it provides fundamental information about the physics beyond the ultrafast driven microstructural modifications and establishes the working limits of the fabricated photonic devices.…”

Buried planar and channel waveguides in sapphire and Ti:sapphire by proton implantation

“…:sapphire active optical waveguides difficult [1][2][3]. The task becomes even more challenging when buried waveguide structures are to be achieved.…”