Silicon nitride stress-optic microresonator modulator for optical control applications

Area of Science:

• Photonics and Optical Engineering
• Materials Science (Silicon Nitride)
• Quantum Technologies

Background:

• Modulation is crucial for controlling photonic components across visible-to-infrared applications.
• Current bulk-optic modulators are bulky, costly, and limit scalability.
• Integrating low-loss, low-power modulators onto wafer-scale platforms like silicon nitride is a key challenge.

Purpose of the Study:

• To develop a low-loss, wafer-scale, CMOS-compatible modulator integrated onto a silicon nitride platform.
• To improve modulator bandwidth, reduce power consumption, and maintain high performance for photonic control.
• To demonstrate the modulator's utility in critical applications like laser stabilization.

Main Methods:

• Integration of a piezo-electric (PZT) actuated micro-ring modulator within a fully-planar silicon nitride platform.
• Characterization of optical loss, bandwidth, extinction ratio, Q-factor, tuning efficiency, and linearity (SFDR, IMD3).
• Demonstration of laser stabilization using a Pound-Drever Hall (PDH) lock loop and laser carrier tracking.

Main Results:

• Achieved ultra-low optical loss (0.03 dB/cm) and high Q-factor (7.1 million) at 1550 nm.
• Demonstrated an order of magnitude increase in bandwidth (DC-15 MHz 3-dB) and reduced power consumption (20 nW).
• Showcased >14 dB extinction ratio, 162 MHz/V tuning efficiency, and excellent linearity (SFDR >65 dB·Hz^2/3).
• Successfully reduced laser frequency noise by 40 dB in a PDH lock loop.

Conclusions:

• The PZT-actuated silicon nitride micro-ring modulator represents a significant advancement for integrated photonics.
• This technology enables miniaturized, low-power, high-performance modulation for diverse visible-to-IR applications.
• Potential applications include atomic/molecular locking, optical frequency combs, quantum computing, and advanced communication systems.