Christopher G. Leburn

Highly efficient 1 GHz repetition-frequency femtosecond Yb3+:KY(WO4)(2) laser

We present a highly efficient, diode-pumped, femtosecond Yb3+:KY(WO4)2 (Yb:KYW) laser operating at a 1.024 GHz repetition rate. The output was centered at a wavelength of 1042 nm and had a bandwidth of 3.8 nm, leading to transform-limited pulses with durations of 278 fs determined by fringe-resolved autocorrelation measurements. The optical-to-optical conversion efficiency and slope efficiency were 61% and 69%, respectively, and the relative intensity noise was <0.1%.

Broadband phase coherence between an ultrafast laser and an OPO using lock-to-zero CEO stabilization

The carrier-envelope-offset frequencies of the pump, signal, idler and related second-harmonic and sum-frequency mixing pulses have been locked to 0 Hz in a 20-fs-Ti:sapphire-pumped optical parametric oscillator, satisfying a critical prerequisite for broadband optical pulse synthesis. With outputs spanning 400 - 3200 nm, this result represents the broadest zero-offset comb demonstrated to date.

Ultrafast nonlinear optics

Measuring Ultrashort Optical Pulses.- Ultra-Broadband Optical Parametric Amplifiers.- Attosecond Generation and High Field Physics.- Advances in Solid-State Ultrafast Laser Oscillators.- Ultrafast Quantum Control in Atoms and Molecules.- Femtosecond Optical Frequency Combs.- Ultrafast Material Science Probed using Coherent X-Ray Pulses from High-Harmonic Generation.- Ultrafast Nonlinear Fibre Optics and Supercontinuum Generation.- Nonlinear Wavelength Conversion and Pulse Propagation in Optical Fibres.- Applications of Ultra-Intense, Short Laser Pulses.- Utilising Ultrafast Lasers for Multiphoton Biomedical Imaging.- Femtosecond Laser Micromachining.- Technology and Applications of Ultrafast Laser Inscription.

87Rb-stabilized 375-MHz Yb:fiber femtosecond frequency comb

We report a fully stabilized 1030-nm Yb-fiber frequency comb operating at a pulse repetition frequency of 375 MHz. The comb spacing was referenced to a Rb-stabilized microwave synthesizer and the comb offset was stabilized by generating a super-continuum containing a coherent component at 780.2 nm which was heterodyned with a (87)Rb-stabilized external cavity diode laser to produce a radio-frequency beat used to actuate the carrier-envelope offset frequency of the Yb-fiber laser. The two-sample frequency deviation of the locked comb was 235 kHz for an averaging time of 50 seconds, and the comb remained locked for over 60 minutes with a root mean squared deviation of 236 kHz.

Femtosecond pulses at 50-W average power from an Yb:YAG planar waveguide amplifier seeded by an Yb:KYW oscillator

We report the demonstration of a high-power single-side-pumped Yb:YAG planar waveguide amplifier seeded by an Yb:KYW femtosecond laser. Five passes through the amplifier yielded 700-fs pulses with average powers of 50 W at 1030 nm. A numerical simulation of the amplifier implied values for the laser transition saturation intensity, the small-signal intensity gain coefficient and the gain bandwidth of 10.0 kW cm(-2), 1.6 cm(-1), and 3.7 nm respectively, and identified gain-narrowing as the dominant pulse-shaping mechanism.

Advances in Solid-State Ultrafast Laser Oscillators

This chapter discusses the fundamentals of modelocking and dispersion control and concentrates on the specific technology of semiconductor saturable absorbers and their implementation in modelocked lasers. The end of the chapter reviews a selection of representative modern ultrafast lasers, which serve as examples of how the techniques discussed in the preceding sections may be implemented in real systems.

Amplification of Femtosecond Pulses from an Yb:KYW Oscillator in a High-power Yb:YAG Planar Waveguide Amplifier

The first demonstration of coupling an Yb:KYW femtosecond laser into a high-power single-side pumped Yb:YAG planar waveguide amplifier is described. Five passes of the amplifier yielded 700 fs pulses with average powers of 50 W.