Yijing Fu

Birefringence and optical power confinement in horizontal multi-slot waveguides made of Si and SiO2

Through simulations and measurements, we show that in multi-slot thin film waveguides, the TM polarized modes can be confined mostly in the low refractive index layers of the waveguide. The structure consisted of alternating layers of a-Si and SiO(2), in the thickness range between 3 and 40 nm, for which the slots were the SiO(2) layers. Simulations were performed using the transfer matrix method and experiments using the m-line technique at 1.55 mum. The dependence of the birefringence and of the power confinement in the slots was studied as a function of the waveguide thickness, the Si and SiO(2) layer thicknesses, and the SiO(2) / Si layer thickness ratio. We find a large birefringence-a refractive index difference between TE and TM modes-as large as 0.8. For TM polarized modes, up to ~ 85% of the total power in the fundamental mode can be confined in the slots.

Strong Er emission from Er doped SiO 2 /nc-Si multilayers

We demonstrate strong Er emission from Er doped SiO2/nc-Si multilayer structures. Compared to reference samples, Er emission is enhanced and nc-Si emission is quenched, indicating energy transfer is the reason behind this enhancement.

Materials and devices for compact optical amplification in Si photonics

Materials and devices.for compact optical amplification in Si photonics is reviewed. In particular, as the requirement for high gain per length together with high refractive index renders traditional oxide-based approach problematic, Er-doping of silicon-rich silicon nitride and erbium silicate nanocrystals are proposed and shown to be promising alternatives. Using such new materials, microdisk resonators and slot waveguides that concentrate the light in a compact volume for high functionality are fabricated and characterized.

Electroluminescence from Er doped SiO 2 /nc-Si multilayers under lateral carrier injection

Light emitting p-i-n diodes consisting of Er-doped SiO 2 /nc-Si multilayers and a novel lateral electrical pumping geometry are demonstrated in forward bias. Erbium electroluminescence and photoluminescence spectra are identical.

Scattering loss of multi-slot silicon light emission device: Theory and experiment

Ever since slot waveguide was first proposed [1][2], its unique photon confinement characteristic has attracted a lot of interest. Its applications in several areas such as silicon light emission device, nonlinear optical device, and optical bio detection have been proposed and experimentally verified [3][4][5]. Different merit functions for device design have also been proposed for some specific applications [6]. We have recently demonstrated the significant advantages of multi-slot waveguide structures, including the very high photon confinement in the lower index material [7], which could make this structure ideal for a laser structures in which electrical pumping takes place in thin Si layers and light is emitted, after energy transfer, from Er atoms located in the thin SiO2 layers. However, scattering losses due to multiple interfaces has not yet been investigated. While low loss single-slot waveguides have been reported [8], no information on loss is available for multi-slot waveguide.

Photon confinement in multi-slot waveguides

We present a multi-layer waveguide that can confine light in low refractive index layers. M-line measurement verified our simulation results. This structure can be used for silicon light emission device because free-carrier losses are avoided.

Light confinement in ridge-type, single mode multi-slot waveguide with Er-doped silica layers

We have fabricated ridge-type, multi-slot waveguides that consist of nanometer-thin Si and Er-doped silica layers. Er ions in the low-index silica region will be used as atom-sized probes for actual power confined in the slot.

Theoretical and experimental demonstration of light confinement in a multi-slot waveguide

We describe an easy-to-fabricate multi-slot waveguide that is able to confine light in the low refractive index regions. Its application for future silicon light emission device is also discussed.