Highly stable fiber-based photonic delay line with large and tunable delay

Area of Science:

• Photonics
• Optical Engineering
• Signal Processing

Background:

• Stable photonic delay lines are critical for applications like large-distance simulations and beamforming.
• Existing technologies face limitations in delay range, stability, and tunability.

Purpose of the Study:

• To demonstrate a fiber-based tunable photonic delay line (TPDL) with enhanced stability and a large, tunable delay range.
• To address environmental-induced delay jitter and enable precise delay adjustments.

Main Methods:

• Implementation of a fiber-based TPDL architecture.
• Utilizing a homodyne phase-locked loop (PLL) for environmental delay jitter compensation.
• Employing reference phase adjustment for precise delay tuning with a 0.5 ps minimum step.

Main Results:

• Achieved a maximum photonic delay of 905 µs.
• Demonstrated exceptional stability with an overlapping Allan deviation (ADEV) of 2.06 × 10⁻¹⁷ at 1000 s averaging time.
• Exhibited delay jitter below 20 fs and precise tunability without losing lock.

Conclusions:

• The developed TPDL offers a unique combination of high stability, wide delay range, and precise tunability.
• This TPDL is well-suited for demanding photonic signal processing, simulations, and beamforming applications.
• The technology represents a significant advancement for applications requiring stable and adjustable optical delays.