Compact multimode waveguide based temperature-insensitive Mach-Zehnder interferometer.

Area of Science:

• Photonics
• Integrated Optics
• Semiconductor Devices

Background:

• Mach-Zehnder interferometers (MZIs) are fundamental optical devices.
• Traditional MZIs often suffer from thermal sensitivity and large footprints.
• Developing compact and stable photonic devices is crucial for advanced applications.

Purpose of the Study:

• To demonstrate a novel multimode waveguide-based Mach-Zehnder interferometer (MZI).
• To achieve a compact footprint and temperature-insensitive operation on a silicon-on-insulator (SOI) platform.
• To evaluate the device's performance in terms of thermal dependence, extinction ratio, and insertion loss.

Main Methods:

• Fabrication of an MZI using a single straight multimode waveguide on an SOI platform.
• Characterization of the device's thermal dependence across a 40nm wavelength range.
• Measurement of transmission spectra, extinction ratio, and insertion loss within the 1545nm-1585nm wavelength range.

Main Results:

• The MZI exhibits a low thermal dependence of approximately 13pm/°C.
• The device demonstrates immunity to local temperature distributions due to its design.
• Measured transmissions show an extinction ratio better than 8dB and minimum insertion loss below 0.31dB.
• The device is compatible with complementary metal-oxide-semiconductor (CMOS) fabrication processes.

Conclusions:

• The proposed multimode waveguide MZI offers a compact and highly stable optical sensing solution.
• The device's temperature-insensitive operation and low loss make it promising for integrated photonic circuits.
• CMOS compatibility facilitates scalable manufacturing and integration into larger systems.