Optoelectromechanical phase shifter with low insertion loss and a 13π tuning range

Area of Science:

• Photonics
• Optoelectronics
• Nanophotonics

Background:

• Integrated photonic devices are crucial for optical communication and signal processing.
• Existing phase shifters often face trade-offs between performance metrics like insertion loss, voltage, and speed.
• Optomechanical devices offer a promising route to novel functionalities in integrated photonics.

Purpose of the Study:

• To present an on-chip optomechanical phase shifter with enhanced performance.
• To demonstrate low insertion loss and low half-wave voltage using a silicon nitride platform.
• To explore the potential for high-speed operation and pulse generation.

Main Methods:

• Fabrication of a phase shifter based on a slot waveguide on a silicon nitride platform.
• Utilizing electrostatic displacement of mechanical structures to modulate the effective refractive index.
• Characterization of insertion loss, extinction ratio, half-wave voltage, and phase shift capabilities.
• Assessment of device operational frequency and pulse generation characteristics.

Main Results:

• Achieved insertion loss below 0.5 dB at 1550 nm.
• Demonstrated a low half-wave voltage (Vπ = 2.0 V) and 2π phase shift (V2π = 2.7 V).
• Measured phase shifts up to 13.3π at 17 V.
• Confirmed MHz range operation and capability for sub-microsecond pulse generation.

Conclusions:

• The developed silicon nitride optomechanical phase shifter offers a compelling combination of low loss, low voltage, and high speed.
• This device represents a significant advancement for integrated photonic applications requiring fast phase modulation.
• The demonstrated performance opens avenues for high-performance optical signal processing and generation of ultrafast optical pulses.