Passive repetition-rate stabilization for a mode-locked fiber laser by electro-optic modulation

Area of Science:

• Optics and Photonics
• Laser Physics

Background:

• Mode-locked fiber lasers are crucial for various applications.
• Stabilizing their repetition rate is essential for precision measurements.
• Existing active feedback methods have limitations in capture range and complexity.

Purpose of the Study:

• To demonstrate a passive stabilization technique for the repetition rate of a mode-locked fiber laser.
• To investigate the underlying mechanism of cross-phase modulation for stabilization.
• To achieve high-precision, wide-bandwidth, and tunable repetition rate stabilization.

Main Methods:

• Utilized an electro-optic modulator in a phase-biased nonlinear amplifying loop mirror.
• Leveraged cross-phase modulation between electrical and optical pulses for spectral shift.
• Employed group velocity dispersion to compensate for cavity-length drift.

Main Results:

• Achieved passive stabilization of the laser repetition rate with a capture range of 2.3 mm.
• Demonstrated robust locking with a fractional instability of 4.3 × 10^-13 over 11 hours.
• Showcased dynamic optical sampling with a 100 kHz refresh rate and 305 ps scanning range.

Conclusions:

• The passive servo action provides a simple and effective method for high-precision laser repetition rate stabilization.
• The technique offers significant advantages in capture range and stability compared to existing methods.
• This approach enables advanced functionalities like dynamic optical sampling with high performance.