Chalcogenide waveguides on a sapphire substrate for mid-IR applications.

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Chalcogenide waveguides are crucial for mid-infrared (mid-IR) applications.
• Sapphire substrates offer potential advantages for optical applications due to their transparency and low loss.

Purpose of the Study:

• To fabricate and characterize arsenic tri-sulfide strip waveguides on a sapphire substrate.
• To evaluate the performance of these waveguides for broadband light guiding.
• To explore the potential of sapphire substrates for enhancing mid-IR chalcogenide waveguide applications.

Main Methods:

• Fabrication of arsenic tri-sulfide strip waveguides on sapphire substrates.
• Measurement of propagation losses using the Fabry-Perot resonator technique.
• Evaluation of refractive index dispersion via transmission spectroscopy.
• Numerical simulations comparing substrate materials and calculating effective refractive index.

Main Results:

• Successfully fabricated arsenic tri-sulfide strip waveguides guiding wavelengths from 0.55 to 5 µm.
• Measured propagation losses of 2.78 dB/cm.
• Demonstrated the suitability of sapphire substrates for mid-IR chalcogenide waveguides.

Conclusions:

• The use of low-loss sapphire substrates redefines the mid-IR operating boundaries for chalcogenide waveguides.
• These waveguides are suitable for both linear and nonlinear optical applications in the mid-IR spectrum.
• The findings pave the way for advanced photonic devices utilizing chalcogenide materials on sapphire.