Mid-infrared waveguide sensors for volatile organic compounds
AssigneeThe Texas A&M University System
InventorPao Tai Lin
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Abstract
Chalcogenide waveguides with high width-to-height aspect ratios and a smooth exposed surfaces can serve as mid-infrared evanescent-absorption-based sensors for detecting and identifying volatile organic compounds and/or determining their concentration, optionally in real-time. The waveguide sensors may be manufactured using a modified sputtering process in which the sputtering target and waveguide substrate are titled and/or laterally offset relative to each other and the substrate is continuously rotated.
Claims20
A method of manufacturing a chalcogenide waveguide on an undercladding of a substrate, an exposed surface of the waveguide being free of edges, the method comprising:
- negatively defining a layout of the waveguide by photolithographically patterning a photoresist layer deposited on the undercladding;
- depositing a chalcogenide layer over the patterned photoresist layer by rotational sputtering, wherein the substrate is tilted or off-set relative to a chalcogenide sputtering target and is further continuously rotated;
- and
- lifting off the photoresist layer.
A sensor device for detecting volatile organic compounds, the sensor device comprising:
- a substrate comprising an undercladding;
- and
- a chalcogenide waveguide created on the undercladding by a process comprising:
- negatively defining a waveguide layout by photolithographically patterning a photoresist layer deposited on the undercladding,
- depositing chalcogenide over the patterned photoresist layer by sputtering while the substrate is continuously rotated and is tilted or off-set relative to a chalcogenide sputtering target, and
- lifting off the photoresist layer.
Dependencies are inferred from the claim text.