B. Stormont

Simplified cavity designs for efficient and compact femtosecond Cr: LiSAF lasers

Abstract We describe efficient, compact femtosecond Cr:LiSAF lasers with a reduced component count that combine greater simplicity with improved performance. We observe transform-limited pulses as short as 136 fs centered on 859 nm at a 470 MHz repetition rate. 20 mW of average output power has been achieved for less than 100 mW of incident diode-laser pump power – an optical-to-optical conversion efficiency of over 20%. We have demonstrated an entirely portable, self-contained, battery-powered version of this laser on a 22×28 cm 2 breadboard, with an electrical-to-optical efficiency of almost 4%. Using four pump laser diodes, we have also achieved operational regimes providing either gigahertz repetition rates or kilowatt peak powers.

Compact Femtosecond Oscillators

Configurations are described for compact femtosecond Cr:LiSAF laser oscillators that operate with low pump-power thresholds. By way of illustration of resonator simplification, a progression of low-loss cavity designs from dual-prism through single-prism to prismless schemes is reviewed. A complete femtosecond laser system is described including the laser diode pump system and drivers that has a footprint as small as 22 cm × 28 cm, and a total electrical drive power of less than 1W! Examples of efficient and rugged femtosecond Yb:tungstate and Cr:YAG lasers are also described together with a brief outline of a demonstration in optical datacomms at rates above 1Tb/s for a scheme incorporating the latter laser.

A vertical extended cavity surface emitting diode laser as an active mirror for controlling mode-locking laser

Controllable mode-locking of a Ti:Sapphire oscillator is demonstrated using an extended vertical cavity surface emitting diode laser as an active-mirror. Modulated modelocking is observed for both reverse and forward pulsed current in the VECSEL.

Tuning of Compact Femtosecond Cr: LiSAF Lasers using a Novel Birefringent Filter Design

Smooth tuning over 30nm is demonstrated by a compact prismless femtosecond Cr:LiSAF laser using broadband negatively dispersive mirrors and a specially designed birefringent filter. 150fs pulses are generated with an electrical-to-optical efficiency exceeding 1%.

Wavelength dependence of induced nonlinear effects in photonic crystal fibre

Summary form only given. In this paper, we report a systematic study of spectral effects at various wavelengths relative to the zero group velocity dispersion (GVD) point in the fibre. The fibres used in our experiments had core diameters of 1.6 /spl mu/m and 2.5 /spl mu/m corresponding to a zero GVD point at 680 nm and 790 nm, respectively. Light from a 10 fs Ti:sapphire laser, centred on 800 nm, was coupled into both of these fibres and the smaller core fibre produced a spectrum corresponding to a four-wave mixing peak in the visible portion of the spectrum and a soliton self-frequency-shifted spectral feature in the near infra-red. The larger core fibre produced an almost continuous spectrum.

High repetition rate fcmtosecond ti: sapphire lasers based on four-element cavities

We demonstrate self-starting, modelocked, four-element cavity Ti: sapphire lasers that operate at 1-2GHz repetition rates. These lasers produce 260-fs pulses and have modelocking thresholds -4OOmW.

Tunable and compact femtosecond Cr:LiSAF lasers: single prism and prismless approaches

50 nm and 30 nm of smooth, continuous tuning is demonstrated in a compact Cr:LiSAF laser using single-prism and prismless approaches respectively. Pulses of /spl sim/150 fs in duration are generated for electrical drive powers of < 1.2 W.