Stable non-volatile phase modulation with antimony-based phase shifter on a broadband silicon nitride platform

Area of Science:

• Materials Science
• Photonics
• Electrical Engineering

Background:

• Silicon photonics is crucial for scalable, low-power photonic integrated circuits (PICs).
• Conventional modulators on silicon nitride platforms face challenges with high power consumption and volatility.
• Phase-change materials (PCMs) offer nonvolatile, low-loss switching with high refractive index contrast (Δn).

Purpose of the Study:

• To demonstrate the integration of an n-doped polysilicon microheater for inducing phase transitions in antimony selenide (Sb2Se3).
• To develop a nonvolatile switching mechanism for silicon nitride-based photonic integrated circuits in the C-band.

Main Methods:

• Fabrication of a device integrating an n-doped polysilicon microheater with antimony selenide (Sb2Se3) on a silicon nitride (SiNx) platform.
• Utilizing controlled electrical pulses to induce reversible phase transitions (amorphous to crystalline) in Sb2Se3.
• Characterization of the device's performance, including phase shift, extinction ratio, and cycling stability in the C-band.

Main Results:

• Achieved a phase shift of 0.43π by switching Sb2Se3 between amorphous and crystalline states.
• Demonstrated nonvolatile switching over 7900 cycles with an extinction ratio up to 12.5 dB.
• Observed minimal variation (±1.9 dB) in extinction ratio over the 7900 cycles.

Conclusions:

• The integrated polysilicon microheater effectively induces nonvolatile phase transitions in Sb2Se3 for photonic switching.
• The demonstrated device shows high stability and performance, suitable for broadband photonic switching applications.
• This approach holds significant potential for scalable, low-power, nonvolatile photonic integrated circuits.