Ultra-flat multicarrier light source based on recirculating frequency shift loop driven by a parity-time symmetric...

Area of Science:

• Optoelectronics
• Photonics
• Signal Processing

Background:

• Advanced light sources are crucial for high-capacity optical communication systems.
• Existing methods often face challenges with phase noise, flatness, and system size.
• Parity-time (PT)-symmetric systems offer unique properties for signal generation.

Purpose of the Study:

• To propose and demonstrate a novel multicarrier light source.
• To investigate the impact of radio frequency (RF) signal side-mode suppression ratio (SMSR) on multicarrier performance.
• To achieve optimized phase noise, flatness, and system miniaturization.

Main Methods:

• Utilizing a recirculating frequency shift loop (RFSL) driven by a PT-symmetric optoelectronic oscillator (OEO).
• Experimentally generating a 10.019 GHz RF signal with a 42 dB SMSR.
• Analyzing the phase noise and flatness of the generated multicarrier signal.

Main Results:

• Achieved a phase noise of -98.63 dBc/Hz at 10 kHz offset frequency (actual noise < -122.87 dBc/Hz).
• Generated up to 120 subcarriers with a flatness of 2.32 dB.
• Demonstrated a total bandwidth coverage of approximately 1.2 THz.

Conclusions:

• The proposed PT-symmetric OEO-driven RFSL is an effective method for generating high-performance multicarrier light.
• The system offers significant improvements in phase noise and flatness, enabling system miniaturization.
• This approach advances the development of compact and efficient multicarrier light sources for optical systems.