Glass optical waveguides: a review of fabrication techniques

Influence of phosphorous precursors on spectroscopic properties of Er3+-activated SiO2-HfO2-P2O5planar waveguides

“…Considering that it has many attractive properties, such as high UV transparency, high mechanical strength, high glass transition temperature, extremely low thermal expansion, and low reflective index, it has various potential uses in many optical devices, such as in waveguides and lasers. However the needs for compact and efficient photonic devices obtained by rare-earth-activated-glasses still drive the research of novel glass composition and optimized fabrication protocols [2,3]. Considering the case of silica glass-based Erbium Doped Waveguide Amplifiers (EDWAs) their short length (around few centimetres) generally imposes a high Er 3+ doping level which may produce clustering effects [4].…”

A novel micro-processing of waveguide coupler in birefringent crystal by twin tracks of single-scan femtosecond laser writing

“…), the focused femtosecond pulses typically induce positive refractive index changes (Δn > 0) in the focal region in most glass materials and a few crystals. 3,11,16 On the other hand, as the femtosecond laser power is increased, negative refractive-index changes (Δn < 0) can be induced in most crystals, and then stress-induced or cladding waveguides can be fabricated. [17][18][19] Particularly, the scales of the cladding waveguide cross section could be designed to match the diameters of different single-and multi-mode fibers.…”

“…9 Several techniques have been utilized to fabricated waveguide couplers, classified into two categories of thin film deposition and index modification. 10,11 Local modification of waveguide coupler fabrications shows various advantages such as low-cost, fast-making, excellent quality and high efficiency, which has been the subject of intense investigation in the past few years, including metal ion thermal indiffusion, ion implantation/irradiation, ion/proton exchange, UV writing and femtosecond laser writing. [11][12][13] Femtosecond laser writing (fs-writing) has become one of the most efficient techniques for direct 3-D microfabrication of optical waveguide devices by micromachining of transparent optical materials in a single-step and mask-less process.…”

Doping silica beyond limits with laser plasma for active photonic materials

“…Furthermore, on-chip integration of both passive and active photonic components is preferred to achieve highly dense optical interconnects. However, such complex multi-level integration demands loss compensating devices to eliminate the optical power losses associated with multi-channel array waveguides, optical power splitters and demultiplexers [6]. The loss-compensated devices can promote cost-effective optical integrations by engaging ultra-low power optical transmitters and economical receivers in the communication network.…”