Integrated NiSi waveguide heaters for CMOS-compatible silicon thermo-optic devices.

Area of Science:

• Photonics
• Materials Science
• Integrated Optics

Background:

• Silicon photonics relies on efficient on-chip optical modulation.
• Thermo-optic modulators offer a viable solution for phase shifting.
• Developing low-power, CMOS-compatible modulators is crucial for scalability.

Purpose of the Study:

• To characterize the performance of Nickel Silicide (NiSi)-based heaters integrated with submicrometer silicon waveguides.
• To evaluate their efficacy as thermo-optic phase shifters in a Mach-Zehnder interferometer.
• To assess power consumption and response time for potential integrated photonic applications.

Main Methods:

• Fabrication of NiSi heaters using a standard complementary metal-oxide-semiconductor (CMOS) silicidation process.
• Integration of heaters with submicrometer silicon rib waveguides.
• Characterization of thermo-optic phase shift performance in a Mach-Zehnder interferometer setup.

Main Results:

• Achieved low power consumption of 20 mW for a pi phase shift (P(pi)) using CMOS-compatible voltages.
• Measured a fast thermo-optic response time constant of less than 2.8 microseconds.
• Demonstrated the effectiveness of NiSi heaters as efficient thermo-optic phase shifters.

Conclusions:

• NiSi-based heaters offer a low-power and fast-response solution for thermo-optic phase shifting in silicon waveguides.
• The CMOS-compatible fabrication process facilitates integration into existing photonic platforms.
• Further reductions in power consumption are anticipated through simulation-driven optimization.