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

Abstract

We demonstrate the stabilization of an all-in-fiber polarization maintaining semi-conductor saturable absorber mirror (SESAM) mode locked frequency comb oscillator with an intra-cavity waveguide electro-optic phase modulator (EOM) to a narrow linewidth HeNe laser over 46 hours. The high feedback bandwidth of the EOM allows a coherent optical lock with an in-loop integrated phase noise of 1.12 rad (integrated from 10 Hz to 3 MHz) from the carrier signal. No piezo fiber stretcher was required to guarantee long-term stabilization, preventing mechanical degradation of the optical fibers and enabling a long lifetime of the oscillator. As an application a hybrid stabilization scheme is presented, where a comb tooth is phase locked to a longitudinal mode of the large ring laser "G" located at the Geodatic Observatory Wettzell. The hybrid stabilization scheme describes the optical lock of the frequency comb to the G laser and the simultaneous compensation of the ring laser frequency drift by comparing the comb repetition rate against an active H-maser reference. In this context the ring laser reached a fractional Allan deviation of 5 · 10 at an integration time of 16384 s.

Recent Advances, Applications, and Perspectives in Erbium-Doped Fiber Combs

“…This EOM served to synchronize the comb with the HeNe transfer laser. Additionally, during the long-term operation of the SESAM fiber comb, there was no reliance on the PZT for locking f r , thereby preventing any degradation in fiber performance caused by mechanical expansion [70]. To enhance the environmental adaptability and expand the application scenarios of optical frequency comb technology, it is necessary to achieve a compact optical comb system.…”

Obtaining more energetic modelocked pulses from a SESAM-based fiber laser

“…In this paper, we present a detailed computational study to optimize the cavity design of a femtosecond fiber laser with a repetition frequency of 300 MHz that is passively modelocked using a semiconductor saturable absorbing mirror (SESAM). SESAMs are now widely used in order to modelock solid-state lasers and waveguide lasers, as well as fiber lasers [9][10][11][12][13][14]. Typically, the response time of these saturable absorbers is longer than the output pulse duration, which leads to experimentally-observed wake mode sidebands [15][16][17].…”

Narrow-linewidth and highly stable optical frequency comb realized with a simple electro-optic modulator system in a mode-locked Er:fiber laser

“…Narrow-linewidth Er:fiber combs are realized not only by the nonlinear polarization evolution (NPE) [11][12][13][14] and nonlinear loop mirror 15,16) mode-locked lasers, but also by semiconductor saturable absorber mirror mode-locked lasers. 17,18) Usually, narrow-linewidth fiber combs use an electro-optic modulator (EOM) as a fast actuator. There are two kinds of EOM used for fiber combs: free-space EOMs, 11,12,16,17) and waveguide EOMs with a fiber pigtail.…”

“…There are two kinds of EOM used for fiber combs: free-space EOMs, 11,12,16,17) and waveguide EOMs with a fiber pigtail. 13,14,18) Each has advantages and disadvantages. Within the free-space EOM case, optical components can be arranged with a certain degree of freedom, but the resulting system may be bulky and fine optical alignment is needed.…”