Wisconsin Alumni Research Foundation

Analytical Instrumentation, Methods & Materials
Analytical Instrumentation Methods Materials
Smoother Waveguides for More Efficient Nonlinear Frequency Conversion
WARF: P120326US01

Inventors: Dan Botez, Thomas Kuech, Luke Mawst, Steven Ruder

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing methods for fabricating orientation-patterned semiconductor structures able to generate visible, mid- or near-infrared light with low optical losses.
For many applications – from remote sensing to laser displays – it is necessary to convert the frequency of light via nonlinear interaction in semiconductor materials. Waveguide devices accomplish this efficiently by receiving radiation from an input source, such as an optical fiber, and directing it along an axis. Upon exiting the other end, the frequency-converted output radiation is collected or redirected for different purposes.

Orientation-Patterned GaAs (OPGaAs) waveguide structures hold promise for efficient, mid-infrared nonlinear frequency conversion. However, thickness variations between the device’s layers can degrade performance.
The Invention
UW–Madison researchers have developed a method for fabricating OPGaAs two-dimensional semiconductor-based waveguides having extremely low layer-interface roughness.

The structure is grown on a template using standard techniques and comprises a core sandwiched between upper and lower cladding layers. The layers have different, periodically arranged crystalline orientations. The surfaces between each layer undergo chemical polishing and isotropic etching that can be done in situ. A high-refractive-index ridge projects above the upper cladding layer and runs along the direction that light propagates. Known lithographic techniques and a combination of wet and dry etching create straight, smooth sidewalls.
  • Laser projection and display
  • Spectroscopy
  • Optical communication
  • Remote sensing
  • Infrared countermeasures
Key Benefits
  • Surface roughness no greater than 10 nanometers
  • Efficient nonlinear frequency  conversion over a broad range
  • Low optical loss
Additional Information
For More Information About the Inventors
Related Intellectual Property
For current licensing status, please contact Michael Carey at [javascript protected email address] or 608-960-9867