Mid-infrared characterization of solution-processed As2S3 chalcogenide glass waveguides

Area of Science:

• Materials Science
• Optical Engineering
• Chemical Sensing

Background:

• Mid-infrared (mid-IR) optical waveguides are crucial for chemical sensing.
• Existing fabrication methods for chalcogenide glass waveguides can be complex and costly, often involving etching processes.

Purpose of the Study:

• To introduce an etch-free, cost-effective method for fabricating mid-infrared chalcogenide glass waveguides.
• To demonstrate the suitability of these waveguides for chemical sensing applications.

Main Methods:

• Fabrication of As(2)S(3) raised strip optical waveguides using a solution-casting technique within soft lithography-defined capillary molds.
• Characterization of mid-IR transmission using a quantum cascade (QC) laser at lambda = 4.8 microm.
• Measurement of optical loss, absorption, and surface roughness.

Main Results:

• Successfully fabricated As(2)S(3) waveguides with dimensions of 40 microm wide by 10 microm thick.
• Achieved optical loss as low as 4.5 dB/cm with optimized substrates and post-processing.
• Optical properties indicate films are suitable for optical devices.

Conclusions:

• The developed solution-processing method is a viable, etch-free alternative for fabricating mid-IR chalcogenide glass waveguides.
• These waveguides show promise for developing advanced mid-IR optical elements and chemical sensors.