A long-term frequency-stabilized erbium-fiber-laser-based optical frequency comb with an intra-cavity electro-optic modulator

TL;DR

This paper presents a long-term frequency-stabilized erbium-doped fiber laser-based optical frequency comb with high stability and a stabilized carrier envelope offset frequency, achieved through intra-cavity electro-optic modulation.

Contribution

It introduces a novel stabilization method for the repetition rate and carrier envelope offset frequency in an erbium fiber laser frequency comb using intra-cavity electro-optic modulation.

Findings

Repetition rate stabilized with 1.6×10⁻¹³ in 1s

Carrier envelope offset frequency deviation of 0.6 mHz at 1s

Achieved high signal-to-noise ratio of 40 dB in f-2f interferometry

Abstract

We demonstrate an optical frequency comb based on an erbium-doped-fiber femtosecond laser with the nonlinear polarization evolution scheme. The repetition rate of the laser is about 209 MHz. By controlling an intra-cavity electro-optic modulator and a piezo-transducer, the repetition rate can be stabilized with high servo bandwidth in a range of 3 kHz, enabling long-term repetition rate phase-locking. The in-loop frequency stability of repetition rate is about 1.6E-13 at 1 second integration time, limited by the measurement system; and it is inversely proportional to integration time in short term. Furthermore, using a common path f-2f interferometer, the carrier envelope offset frequency of the frequency comb is obtained with a signal-to-noise ratio of 40 dB in 3 MHz resolution bandwidth. Stabilized carrier envelope offset frequency exhibits a deviation of 0.6 mHz at 1 second integration time.