Long-term Hybrid Stabilization of the Carrier-Envelope Phase

TL;DR

This paper introduces a hybrid stabilization method for the carrier-envelope phase in mode-locked lasers, combining fast feed-forward and slow feedback techniques, achieving 75 hours of stable operation with minimal phase noise.

Contribution

It presents the first long-term hybrid stabilization system for CEP in a mode-locked laser, integrating feed-forward and feedback methods for improved stability.

Findings

75 hours of continuous CEP stabilization achieved

Integrated phase noise of 14 mrad over 1 Hz to 3 MHz

Environmental factors affect long-term stability

Abstract

Controlling the carrier envelope phase (CEP) in mode-locked lasers over practically long timescales is crucial for real-world applications in ultrafast optics and precision metrology. We present a hybrid solution that combines a feed-forward technique to stabilize the phase offset in fast timescales and a feedback technique that addresses slowly varying sources of interference and locking bandwidth limitations associated with gain media with long upper-state lifetimes. We experimentally realize the hybrid stabilization system in an Er:Yb:glass mode-locked laser and demonstrate 75 hours of stabilization with integrated phase noise of 14 mrad (1 Hz to 3 MHz), corresponding to around 11 as of carrier to envelope jitter. Additionally, we examine the impact of environmental factors, such as humidity and pressure, on the long-term stability and performance of the system.