Fundamentally mode-locked, femtosecond waveguide oscillators with multi-gigahertz repetition frequencies up to 15 GHz

Alexander A. Lagatsky,Wilson Sibbett,Amol Choudhary,Pradeesh Kannan,David P. Shepherd,Christian T. A. Brown

doi:10.1364/oe.21.019608

Abstract

We demonstrate passively mode-locked Yb(3+)-doped glass waveguide lasers in a quasi-monolithic configuration with a maximum pulse repetition frequency up to 15.2 GHz. A semiconductor saturable absorber mirror (SESAM) is used to achieve stable mode-locking around 1050 nm with pulse durations as short as 811 fs and an average power up to 27 mW. Different waveguide samples are also employed to deliver pulses with repetition rates of 4.9 GHz, 10.4 GHz and 12 GHz with an average power of 32 mW, 60 mW and 45 mW, respectively. The group velocity dispersion control in the cavity is provided by changing the gap between the SESAM and the waveguide end-face to facilitate a soliton mode-locking regime.

Highlights

There has been a recent focus on the development of ultrafast laser sources with high (> 1 GHz) pulse repetition frequencies (PRF) owing to their various applications in non-linear microscopy [1], optical sampling [2], arbitrary optical waveform generation [3], optical communications [4], frequency metrology [5] and “astro-combs” [6]
That the value of the Group velocity dispersion (GVD) depends very sensitively on the Gires-Tournois interferometer (GTI) gap (~80 fs2/nm) and, we have provided a precise control of the gaps, it was not possible to fully balance the second order dispersion and the self-phase modulation which explains the generation of slightly chirped pulses
Diode-pumped solid-state waveguide lasers were demonstrated with fundamental PRFs in the range of 4.9-15.2 GHz

Summary

Introduction

There has been a recent focus on the development of ultrafast laser sources with high (> 1 GHz) pulse repetition frequencies (PRF) owing to their various applications in non-linear microscopy [1], optical sampling [2], arbitrary optical waveform generation [3], optical communications [4], frequency metrology [5] and “astro-combs” [6]. These applications drive a desire for a multi-GHz ultrafast source that is compact, power scalable at low noise performance, mass producible and relatively low-cost. Using carefully engineered cavity configurations repetition rates exceeding 100 GHz have been achieved from a bulk solid-state laser [14]

Methods

Results

Conclusion