Modulation-free laser stabilization with aided acquisition for extended locking range

Area of Science:

• Photonics
• Optical Engineering
• Laser Physics

Background:

• Stable lasers are crucial for precision optical systems, but conventional stabilization methods face limitations in noise suppression, scalability, and locking range.
• Achieving long-term stability in lasers requires advanced techniques to manage phase noise and maintain consistent operation.

Purpose of the Study:

• To propose and demonstrate a novel modulation-free laser stabilization system.
• To improve laser frequency noise suppression and extend the locking range using integrated photonics.
• To offer a compact and scalable solution for low-noise lasers.

Main Methods:

• Integration of a cavity-coupled Mach-Zehnder interferometer (CCMZI) with an aided acquisition (AAQ) system.
• Fabrication of the CCMZI-AAQ system on a low-loss silicon nitride (SiN) photonic integrated chip.
• Experimental validation of the system's performance in noise suppression and locking range.

Main Results:

• Achieved over 36 dB of laser frequency noise suppression at a 1 kHz offset frequency.
• Extended the locking range to the full free spectral range (FSR) of 3.95 GHz, an order-of-magnitude improvement.
• Demonstrated a compact (5.43 mm²) and scalable photonic chip solution.

Conclusions:

• The developed CCMZI-AAQ system offers a significant advancement in laser stabilization technology.
• The system provides a compact, scalable, and high-performance solution for integrated low-noise lasers.
• Potential applications include fiber sensing, optical communication, and other precision optical systems.