All-optical microwave oscillator based on a mutual-injection coupling between DFB-LDs.

Area of Science:

• Photonics
• Optoelectronics
• Microwave Engineering

Background:

• Traditional microwave oscillators often rely on electronic components, limiting performance and stability.
• All-optical approaches offer potential advantages in terms of bandwidth, phase noise, and miniaturization.

Purpose of the Study:

• To propose and experimentally demonstrate a novel all-optical microwave oscillator (AOMO).
• To achieve a highly stable and tunable microwave signal generation using only optical components.

Main Methods:

• Utilizing a mutual injection loop with two distributed feedback laser diodes (DFB-LDs).
• Leveraging period-one (P1) oscillation in one DFB-LD as the microwave seed signal.
• Employing optical injection locking and optical-optical modulated effects for signal enhancement and stabilization.

Main Results:

• Demonstrated a highly stable single-mode microwave signal at 16.69 GHz.
• Achieved a single-sideband (SSB) phase noise of -90.7 dBc/Hz at 10 kHz offset.
• Showcased wide frequency tunability from 14.48 GHz to 21.45 GHz.

Conclusions:

• The proposed AOMO design offers a promising solution for generating high-performance microwave signals.
• The all-optical approach simplifies the oscillator structure and enhances stability and tunability.
• This technology has potential applications in advanced communication and sensing systems.