F. Al-Saab

A self-coupling multi-port microcoil resonator

A new type of self-coupling multi-port microcoil resonator using a microfiber coupler is presented. The microresonators, a simple combination of a microfiber coupler and microcoil resonator, were fabricated by coiling a four port microfiber coupler around a low index support rod to induce optical resonance via coupling between adjacent turns. Light propagates along the coil whilst the beating between the supermodes of the coupler is still present, giving an increased extinction ratio and an output spectrum strongly dependent on the microfiber coupler diameter. The multiport microcoil resonator was embedded in a low refractive index polymer to improve its robustness and the polarization dependence was further analyzed.

Chalcogenide glass photonics: Non-volatile, bi-directional, all-optical switching in phase-change metamaterials

Non-volatile, bi-directional, all-optical switching in a phase-change metamaterial delivers high-contrast transmission and reflection modulation at visible and infrared wavelengths in device structures only ~1/8 of a wavelength thick.

Strain engineering in graphene by laser irradiation

We demonstrate that the Raman spectrum of graphene on lithium niobate can be controlled locally by continuous exposure to laser irradiation. We interpret our results in terms of changes to doping and mechanical strain and show that our observations are consistent with light-induced gradual strain relaxation in the graphene layer.