Thomas P. Pearsall

Experimental and theoretical confirmation of Bloch-mode light propagation in planar photonic crystal waveguides

The dispersion diagram of the leaky modes in the planar photonic crystal waveguide is experimentally obtained for the wavelengths from 1440 to 1590 nm. A small stop band, around wavelength 1500 nm, is detected. The experimentally obtained results are in very good agreement with our three-dimensional finite difference time domain calculations. Propagation losses of the leaky modes are estimated and we have found that they decrease as we approach the ministop band.

Optical pumping and the valence‐band light‐hole effective mass in GaxIn1−xAsyP1−y (y≃2.2x)

We report the use of optical pumping in p‐type GaxIn1−xAsyP1−y nearly lattice‐matched to InP. Analysis of the conduction‐electron spin‐polarized photoluminescence has been used to deduce the valence‐band light‐hole effective mass as a function of alloy composition. Our results are in good agreement with masses calculated using the k⋅p approximation.

Nanophotonics based on planar photonic crystals

Summary form only given. By creating different types of defects in the photonic crystal lattice, various nanophotonics components, such as cavities and waveguides, can be realized. The quest for a compact and efficient nano-cavity, with high quality factor (Q) and small mode volume (V/sub mode/), has been a central part of research in integrated optics. Recently, we have proposed a systematic method to design optical nano-cavities that satisfy both of these requirements. The cavity consists of a defect hole that is smaller than surrounding holes arranged in the triangular lattice photonic crystal. In order to test our design we have fabricated high-Q cavities in the InGaAsP material system.

Waveguiding at 1550 nm using photonic crystal structures in silicon on insulator wafers

Design, fabrication and light guiding in planar photonic crystal structures including sharp corners with a bending radius less than 1 micron are demonstrated at 1550 nm wavelength in silicon waveguides on silicon dioxide substrates. Photon confinement in the sample plane was achieved by a photonic crystal structure while confinement in the vertical direction was achieved by index of refraction contrast.

Waveguiding at 1500 nm using photonic crystal structures in silicon on insulator wafers

Summary form only given. Planar photonic crystal waveguides and devices may offer the possibility to build photonic circuits with greater density and new functionality compared to existing waveguide devices that are based on the control of light by refraction. The primary vehicles for this research are the study of microcavity lasers as a path to understanding new functionality, and the propagation of light around sharp bends as the path to increasing the packing density of planar optical circuits. We report our results on the successful demonstration of coupling and guiding of light in a planar photonic circuit incorporating sharp bends. Photonic crystal structures were designed to confine light in a silicon waveguide at 1500 nm, by drilling air holes at periodic intervals around the waveguide region. Both square and hexagonal structures have been studied. The pattern design was transferred to a silicon-on-insulator wafer using direct-write e-beam lithography. The pattern was etched into the silicon layer by chemically assisted ion beam etching (CAIBE).

Experimental characterization of dispersion properties of the leaky modes in planar photonic crystal waveguide

We have experimentally obtained the dispersion diagram of the leaky modes in a planar photonic crystal waveguide for wavelengths from 1440 nm to 1590 nm. A small stop band around /spl lambda/=1500 nm is also detected. The experimental results are in very good agreement with our 3D FDTD calculations.

Experimental characterization of dispersion properties of leaky modes in planar photonic crystal waveguide

We have experimentally observed the coupling of a Bloch wave in a single-line-defect planar photonic crystal and have mapped the dispersion diagram of the leaky mode component of this wave. The results are in excellent agreement with our three-dimensional finite difference time domain calculations.

Waveguiding in planar photonic crystals

Photonic crystal planar circuits designed and fabricated in silicon on silicon dioxide are demonstrated. Our structures are based on two-dimensional confinement by photonic crystals in the plane of propagation, and total internal reflection to achieve confinement in the third dimension. These circuits are shown to guide light at 1550 nm around sharp corners where the radius of curvature is similar to the wavelength of light.

Planar Photonic Crystal

We present results of guiding light in a single-line-defect planar photonic crystal (PPC) waveguide with 90° and 60° bends. The wave guiding is obtained by total internal reflection perpendicular to the plane of propagation and by the photonic band gap for the 2D photonic crystal in the plane. The results for photonic waveguiding are shown and demonstrated at 1.5 μm wavelength.