Tunable single-mode microwave signal generation utilizing an all-optical coupled microwave oscillator

Area of Science:

• Photonics
• Microwave Engineering
• Optical Communications

Background:

• Traditional microwave oscillators often rely on electrical components, limiting performance and integration.
• All-optical approaches offer potential advantages in terms of speed, bandwidth, and immunity to electromagnetic interference.

Purpose of the Study:

• To propose and experimentally demonstrate a tunable all-optical coupled microwave oscillator.
• To achieve microwave signal generation without photoelectric conversion or electro-optic modulation.

Main Methods:

• Utilizing a fiber ring laser as both a frequency reference and an active optical resonator.
• Employing cavity mode transfer and injection locking for oscillation frequency selection.
• Implementing microwave envelope detection and feedback modulation in a semiconductor optical amplifier (SOA).

Main Results:

• Successful generation of high-quality, single-mode microwave signals.
• Achieved frequency tunability from 6.93 GHz to 25.54 GHz by adjusting the master laser wavelength.
• Measured single-sideband phase noise of approximately -95 dBc/Hz at a 10-kHz offset.

Conclusions:

• The proposed all-optical microwave oscillator is a viable and tunable solution.
• The system demonstrates the potential for all-optical microwave signal generation with excellent stability and phase noise performance.