Long-term femtosecond timing link stabilization using a single-crystal balanced cross correlator.

Area of Science:

• Optics and Photonics
• Nonlinear Optics
• Optical Metrology

Background:

• Precise timing distribution is crucial for modern scientific experiments and communication networks.
• Existing balanced cross correlators often require multiple components and complex alignment.
• The development of compact and robust timing stabilization systems is an ongoing challenge.

Purpose of the Study:

• To demonstrate a simplified, self-aligned balanced cross correlator.
• To investigate its application in stabilizing optical fiber links for timing distribution.
• To achieve high-precision timing stability over extended fiber lengths.

Main Methods:

• Utilizing a single type-II phase-matched periodically poled potassium titanyl phosphate (KTiOPO4) crystal.
• Exploiting the crystal's birefringence to induce walk-off between orthogonally polarized pulses.
• Implementing the device for active stabilization of a 310 m optical fiber link.

Main Results:

• Successful demonstration of a self-aligned balanced cross correlator in a single crystal.
• Achieved balancing of the cross correlator with input pulses at the same center wavelength.
• Stabilized a 310 m optical fiber link with long-term stable 10 femtosecond (fs) precision.

Conclusions:

• The single-crystal balanced cross correlator offers a simplified and effective solution for optical timing.
• This technology enables robust and high-precision timing distribution over optical fiber links.
• The demonstrated performance paves the way for advanced applications requiring femtosecond-level timing accuracy.