We fabricate a saturable absorber mirror by coating a graphene film on an output coupler mirror. This is then used to obtain Q-switched mode-locking from a diode pumped linear cavity waveguide laser inscribed in Ytterbium-doped Bismuthate Glass, with high slope and optical conversion efficiencies. The laser produces mode-locked pulses at∼1039nm, with 1.5GHz repetition rate at an average 202mW output power. This performance is due to the combination of the graphene saturable absorber with the high quality laser glass.

Laser slope efficiencies close to the quantum defect limit and in excess of 78% have been obtained from an ultrafast laser inscribed buried channel waveguide fabricated in a ytterbium-doped bismuthate glass. The simultaneous achievement of low propagation losses and preservation of the fluorescence properties of ytterbium ions is the basis of the outstanding laser performance.

Ultrafast fiber lasers, with their distinct features of high stability, superior beam quality, compactness and power scalability have revolutionized a variety of applications, ranging from micromachining and medical diagnostics to basic research. One of the applications include Ultrafast Laser Inscription, a technology that has considerably improved and diversified with advances in stable, high power Ytterbium-doped fiber lasers. This paper explores the highly interdisciplinary application realm of Ultrafast Laser Inscription for the development of novel photonic and optofluidic devices. Quantum Sciences. His current projects involve amplifiers for telecommunications, ultrafast laser inscription (ULI) for novel optoelectronic device applications, generation of white light continuum from visible to mid-infrared part of the spectrum, and the development of ULI based microfluidic devices for biophotonics applications. He has pioneered Photonics

We present an evanescent-field device based on a right-angled waveguide. This consists of orthogonal waveguides, with their points of intersection lying along an angled facet of the chip. Light guided along one waveguide is incident at the angled dielectric-air facet at an angle exceeding the critical angle, so that the totally internally reflected light is coupled into the second waveguide. By depositing a nanotube film on the angled surface, the chip is then used to mode-lock an Erbium doped fiber ring laser with a repetition rate of 26 MHz, and pulse duration of 800 fs. V