Towards a space-qualified Kerr-lens mode-locked laser

Powerful 1-µm 1-GHz optical frequency comb

A self-referenced optical frequency comb is presented based on Kerr-lens mode-locking of ytterbium-doped CALGO. The robust source delivers 3.5 W average power in 44 fs-long pulses at 1 GHz repetition rate. The residual root-mean-square timing jitter of the emitted pulse-train is 146 fs and the residual integrated phase noise of the carrier-envelope offset frequency is 107 mrad, both in a span from 1 Hz to 10 MHz. After stabilization, 2.7 W average power remains for direct application. This work represents the first multi-mode pumped Kerr-lens mode-locked optical frequency comb at gigahertz-level repetition rate.

Misalignment-free, Kerr-lens-modelocked Yb:Y2O3 2.2-GHz oscillator, amplified by a semiconductor optical amplifier

We present a fully bonded, misalignment-free, diode-pumped Yb:ceramic (Yb:Y₂O₃) oscillator producing 190-fs pulses at a repetition frequency of 2.185 GHz. Self-starting Kerr-lens-modelocked operation was obtained from both outputs of the ring cavity with an average combined output power of 14-30 mW for pump powers from 380-670 mW. The fully bonded design provided self-starting, turnkey operation, with a relative intensity noise of 0.025% from 1 Hz-1 MHz. Tuning of the pulse repetition rate over a 120 kHz range was demonstrated for a 2°C change in temperature. Chirped-pulse amplification in a semiconductor optical amplifier was shown to increase the pulse average power to 69 mW and the pulse energy (peak power) from 2.5 pJ (12 W) to 32 pJ (71 W).

Three-element, self-starting Kerr-lens-modelocked 1-GHz Ti:sapphire oscillator pumped by a single laser diode

We present a Kerr-lens-modelocked, three-element, diode-pumped Ti:sapphire laser producing 111-fs pulses at a repetition frequency of 1.02 GHz. Self-starting soliton-modelocked operation with an output power of 106 mW was obtained when the laser was pumped at 1.0 W with a single 527-nm laser diode. The output exhibits a relative intensity noise of 0.06% (1 Hz - 1 MHz) and locking of the repetition rate to an external reference is demonstrated with a phase error of 1.7 mrad (1 Hz-1 MHz). The simplicity of the laser makes it an attractive candidate as a module for integration into larger systems.

Kerr-lens mode-locked ytterbium-activated orthoaluminate laser

We report on the first, to the best of our knowledge, Kerr-lens mode-locked laser based on an Yb³⁺-doped perovskite-type orthoaluminate crystal exploiting two different principal light polarizations. The Yb:(Y,Gd)AlO₃ laser delivers soliton pulses as short as 32 fs at 1067 nm with an average output power of 328 mW and a pulse repetition rate of ∼84.6 MHz for E || a polarization. For the orthogonal E || b polarization, 33-fs pulses are generated at 1057 nm with an average output power of 305 mW. Power scaling to a maximum average output power reaching 2.07 W is achieved at the expense of longer pulse duration (72 fs for E || b), corresponding to an optical efficiency of 43.9% and a peak power of 303 kW.