Erwin Bente

Development of high average power picosecond laser systems

The use of semiconductor saturable absorbers has emerged as an enabling technology in modern passively modelocked laser systems. Their application to high power picosecond lasers, most notably Nd-doped lasers, has produced systems with average power levels of a few tens of watts. In this paper, the development of these laser systems to the 100W level and above will be outlined.

GaInNAs VCSEL structure as a modelocking element for a 1.3 /spl mu/m Nd:YVO/sub 4/ laser

Summary form only given. In this paper we present recent results obtained on passive modelocking of a Nd:YVO/sub 4/ laser operating at 1342 nm using a semiconductor saturable absorber mirror (SESAM) using the novel semiconductor material system GaInNAs/GaAs. This material system has been receiving considerable attention in the development of laser diodes operating at the 1.3 /spl mu/m optical fiber window. A principal advantage of GaInNAs is that it can be conveniently grown on GaAs which enables the use of high refractive index contrast AlGaAs-based distributed Bragg reflectors that provide a good bandwidth and simplifies manufacture.

A high average power, high repetition rate, electro-optically Q-switched diode pumped laser system

Summary form only given. In this paper results are presented of the development of an all solid-state 15 Watt, 20 kHz repetition rate Q-switched laser oscillator with a 15 ns pulse length and a good beam quality. This laser system is particularly suitable for driving non-linear optics and machining applications. Nd:YVO/sub 4/ was chosen for the laser material for a number of reasons. Its high stimulated emission cross-section enables the production of relatively short Q-switched pulses with modest pulse energies, the output is well polarized without the need for a polariser, the Q-switch does not require a polariser and the thermal lensing is less than in Nd:YAG in a similar set up.

Side-pumped multiwatt Nd:YVO4 laser mode-locked by a semiconductor saturable Bragg reflector

We report on a side-pumped and passively mode-locked all- solid-state laser. The laser consists of an astigmatically compensated resonator with a saturable Bragg reflector to achieve mode locking and a Brewster-cut Nd:YVO4 rod, which is side-pumped by a diode-laser bar. At 17 W of pump power a fundamental-mode average output power of 4.4 W was attained. Pulses as short as 33 ps have been measured at pulse repetition rates of 235 MHz and 440 MHz. When synchronously pumping an optical parametric oscillator (OPO), these pulse durations lead to wide cavity length detuning tolerances and a comparatively narrow spectral bandwidth of < 15 GHz which is very suitable for applications such as molecular spectroscopy and pollutant detection. A pump depletion of 78% and 1 W of signal output power between 1461 nm and 1601 nm were obtained from an OPO based on periodically poled lithium niobate.