All-in-fiber SESAM based comb oscillator with an intra-cavity electro-optic modulator for coherent high bandwidth...

Area of Science:

• Optical Physics
• Laser Technology
• Frequency Metrology

Background:

• Frequency combs are crucial for high-precision measurements.
• Stabilizing fiber laser oscillators is challenging due to environmental factors.
• Existing stabilization methods often rely on mechanical components, limiting long-term performance.

Purpose of the Study:

• To demonstrate long-term stabilization of a fiber laser frequency comb.
• To achieve stabilization using an intra-cavity electro-optic phase modulator (EOM).
• To present a hybrid stabilization scheme for a large ring laser.

Main Methods:

• Utilized an all-in-fiber polarization maintaining semiconductor saturable absorber mirror (SESAM) mode-locked frequency comb oscillator.
• Employed an intra-cavity waveguide electro-optic phase modulator (EOM) for feedback control.
• Locked the comb to a narrow linewidth HeNe laser and applied a hybrid scheme to a large ring laser.

Main Results:

• Achieved stable optical lock over 46 hours with an in-loop integrated phase noise of 1.12 rad.
• Eliminated the need for piezo fiber stretchers, preventing mechanical degradation.
• Demonstrated a fractional Allan deviation of 5 × 10^-16 for the ring laser at 16384 s integration time.

Conclusions:

• The EOM-based stabilization provides a robust and long-lasting solution for fiber laser frequency combs.
• The hybrid stabilization scheme successfully locks a comb tooth to a ring laser and compensates for its frequency drift.
• This work advances high-precision optical frequency standards and metrology applications.