Spectrally broadband electro-optic modulation with nanoelectromechanical string resonators.

Area of Science:

• Photonics
• Microelectromechanical Systems (MEMS)
• Nanotechnology

Background:

• Electro-optical modulators are crucial for optical communication and signal processing.
• Existing modulators often face limitations in modulation depth, driving voltage, or operating frequency.
• MEMS-based approaches offer potential for miniaturization and enhanced performance.

Purpose of the Study:

• To present a novel shutter-based electro-optical modulator utilizing nanoelectromechanical silicon nitride string resonators.
• To demonstrate high optical modulation depth and low driving voltage.
• To explore the frequency tuning capabilities of the device.

Main Methods:

• Fabrication of parallel silicon nitride string resonators with gold electrodes.
• Actuation of strings via Lorentz or electrostatic forces to modulate gap width.
• Modulation of focused laser light passing through the modulated gap.
• Operation in the strongly nonlinear regime for frequency tuning.

Main Results:

• Achieved optical modulation depth close to 100%.
• Required driving voltage below 1 mV at 314 kHz.
• Demonstrated frequency tuning of several kilohertz without significant loss in modulation depth.
• Resonance frequencies in the range of hundreds of kilohertz to several megahertz.

Conclusions:

• The developed electro-optical modulator offers exceptional performance in modulation depth and driving voltage.
• The device's frequency tunability in the nonlinear regime is a significant advantage for various applications.
• This technology holds promise for advanced optical modulation and signal processing systems.