University of Illinois

Xin Yu

Lynford L Goddard

Gang Logan Liu

Chris Edwards

Lonna Edwards

Terry Koker

Kaiyuan Wang

Milton Feng

Xiuling Li

Placid M Ferreira

Wen Huang

Samuel Washington

Shailendra Srivastava

Julianne Lee

Catherine Britt Carlson

Vertical-cavity surface-emitting lasers (VCSELs) and methods for making such are provided. The VCSELs include stepped upper reflectors having respective differently-sized apertures. This allows the lower portion of the reflector to have formed therein a wider-diameter aperture to allow for increased current injection. The upper portion of the reflector has formed therein a narrower-diameter, mode-selecting aperture to allow higher-order modes to be reduced, leading to single-mode operation. The VCSELs are thus capable of higher-power emission in a single mode, allowing for longer-distance signaling over optical fiber, despite modal dispersion within the fiber and/or at the coupling between the VCSEL and the fiber. The two differently-sized apertures can be formed via respective lateral oxidation processes following etch-down to form the respective steps of the upper reflector. Differences in composition across the upper reflector results in temperature-dependence of the oxidation process, allowing the apertures to be formed with different sizes.

Single mode VCSELs with low threshold and high speed operation

Methods and apparatus for subtractively fabricating three-dimensional structures relative to a surface of a substrate and for additively depositing metal and dopant atoms onto the surface and for diffusing them into the bulk. A chemical solution is applied to the surface of the semiconductor substrate, and a spatial pattern of electron-hole pairs is generated by projecting a spatial pattern of illumination characterized by a specified intensity, wavelength and duration at each pixel of a plurality of pixels on the surface. Charge carriers are driven away from the surface of the semiconductor on a timescale short compared to the carrier recombination lifetime. Such methods are applied to creating a spatially varying doping profile in the semiconductor substrate, a photonic integrated circuit and an integrated photonic microfluidic circuit.

Spectrally and temporally engineered processing using photoelectrochemistry

Methods and apparatus for subtractively fabricating three-dimensional structures relative to a surface of a substrate and for additively depositing metal and dopant atoms onto the surface and for diffusing them into the bulk. A chemical solution is applied to the surface of the semiconductor substrate, and a spatial pattern of electron-hole pairs is generated by projecting a spatial pattern of illumination characterized by a specified intensity, wavelength and duration at each pixel of a plurality of pixels on the surface. An electrical potential is applied across the interface of the semiconductor and the solution with a specified temporal profile relative to the temporal profile of the spatial pattern of illumination. Such methods are applied to the fabrication of a photodetector integral with a parabolic reflector, cell size sorting chips, a three-dimensional photonic bandgap chip, a photonic integrated circuit, and an integrated photonic microfluidic circuit.

A rolled-up inductor structure for a radiofrequency integrated circuit (RFIC) comprises a multilayer sheet in a rolled configuration comprising multiple turns about a longitudinal axis. The multilayer sheet comprises a conductive pattern layer on a strain-relieved layer, and the conductive pattern layer comprises at least one conductive strip having a length extending in a rolling direction. The at least one conductive strip thereby wraps around the longitudinal axis in the rolled configuration. The conductive pattern layer may also comprise two conductive feed lines connected to the conductive strip for passage of electrical current therethrough. The conductive strip serves as an inductor cell of the rolled-up inductor structure.

Rolled-up inductor structure for a radiofrequency integrated circuit (RFIC)

Growing community of inventors

Urbana, IL, United States of America

Xin Yu