Electrically controlled 1  ×  2 tunable switch using a phase change material embedded silicon microring

Area of Science:

• Photonics
• Materials Science
• Electrical Engineering

Background:

• Phase change materials like germanium antimony telluride (GST) are crucial for advanced photonic devices.
• GST offers high optical contrast, bi-stability, and rapid response, making it ideal for optical switching.

Purpose of the Study:

• To propose and analyze a 1x2 tunable optical switch.
• To leverage GST's phase change properties and thermo-optic coefficient in a silicon microring resonator design.

Main Methods:

• Fabrication of a silicon microring resonator integrated with a 1 µm GST layer.
• Electrical induction of phase transitions in GST to control optical switching.
• Characterization of device performance including extinction ratios, switching times, and wavelength tunability.

Main Results:

• Achieved high extinction ratios of 25.57 dB (through port) and 18.75 dB (drop port).
• Demonstrated fast switching times: ~66 ns (amorphous to crystalline) and ~45 ns (crystalline to amorphous).
• Reported a resonance wavelength shift of 0.661 nm/µm and tuning efficiency of 1.16 nm/mW, with a large wavelength tunability of 4.63 nm.

Conclusions:

• The proposed GST-embedded silicon microring resonator functions as an effective tunable optical switch.
• The device's performance metrics make it suitable for reconfigurable photonic integrated circuits.
• Electrical control of GST phase transitions provides a viable mechanism for optical switching applications.