Malte Duering

Compact high-power optical source for resonant infrared pulsed laser ablation and deposition of polymer materials.

We propose a novel tuneable table-top optical source as an alternative to the free electron laser currently used for resonant infrared pulsed laser deposition of polymers. It is based on two-stage pulsed optical parametric amplification using MgO doped periodically poled lithium niobate crystals. Gain in excess of 10(6) in the first stage and pump depletion of 58% in the second stage were achieved when the system was pumped by a high-power Nd:YVO(4) picosecond laser source at 1064 nm and seeded by a CW tuneable diode laser at 1530 nm. An average power of 2 W was generated at 3.5 microm corresponding to 1.3 microJ pulse energy.

Corrections to refractive index data of stoichiometric lithium tantalate in the 5-6 μm range

We propose corrections to the coefficients in the published Sellmeier equation for stoichiometric LiTaO3 [Opt. Lett.28, 194 (2003)] that allow the extension of the wavelength range within the region of midinfrared absorption edge up to 6 microm. The required extraordinary refractive index data for this range were obtained using single-pass optical parametric fluorescence measurements with a pump wavelength of 1064.4 nm. We also observed efficient parasitic second-harmonic generation that could affect some quasi-phase-matching interactions. The corrected Sellmeier equation improves the accuracy of poling period calculations where the idler wavelength is within the region.

Generation of tuneable 589nm radiation as a Na guide star source using an optical parametric amplifier

We describe a 5.5W 589 nm source based on a passively mode-locked Nd:YVO4 laser and a multi-stage Lithium Triborate optical parametric amplifier seeded by a tuneable semiconductor laser. We show this system can produce rapidly tuneable, transform-limited pulses in near diffraction-limited beams at 589 nm, useful for Na guide star applications. The attraction of this scheme is that it can be assembled from commercially available hardware and is readily scalable to high average powers.

Resonant infra-red pulsed laser ablation of polymers with single picosecond pulses generated by an optical parametric amplifier

We have used a mid-IR optical parametric amplifier for single pulse ablation of polystyrene via resonant infra-red pulsed laser ablation.

Multistage optical parametric amplifier for the generation of sodium guide star

We report proof-of-concept experiments generating 5.5W of rapidly tuneable 589nm laser radiation through SHG of 1178nm radiation generated by optical parametric amplification in Lithium Triborate. The two stage OPA was pumped by a frequency doubled mode-locked Nd:YVO4 laser (15ps, 1.5MHz, 50W) and seeded by a tuneable diode laser, allowing convenient tuning on and off the Na D2 line. Our findings imply that if scaled up in power and with modified pump pulse duration, this approach can lead to a versatile high-power Na guide star source which can be built from readily available commercial components.

A simple scalable solid-state 589nm laser guide star source based on optical parametric amplifiers

We describe a new method for producing high power coherent light at 589 nm based on a scalable, passively mode-locked, Nd:YVO4 laser and a seeded optical parametric amplifier. Average powers of 4.6 W at 589 nm have been produced.

Solid-state laser source for resonant infra-red pulsed laser deposition of polymers

We report on a solid-state laser source for resonant infra-red pulsed laser deposition of polymers. Employing two stage optical parametric amplification using MgO:PPLN crystals it is tuneable from 3.2 mum to 3.6 mum.

High-gain optical parametric amplifier as a key element of a polymer ablation and deposition system

This study reports preliminary results on the performance of a high-gain optical parametric amplifier (OPA). This high-tunable laser source based on a MgO doped periodically poled lithium niobate crystal is considered a key element of a polymer ablation and deposition system.

Corrections to the Sellmeier coefficients of stoichiometric lithium tantalate for wavelengths near the mid-infrared absorption edge

This paper reports on the corrections to the Sellmeier coefficients of stoichiometric lithium tantalate in the mid-infrared range. This allows more accurate calculation of the quasi-phase-matching (QPM) poling period for any particular QPM interaction.

Applications of High Power Slow Mode-locked Lasers for Ablation and Non-linear Optics

High average power (10-50W) slow mode-locked lasers operating with repetition rates of a few MHz provide a unique combination of high peak power, short pulse duration, and high brightness that makes them ideal for applications in pulsed laser ablation and nonlinear optics. With peak powers in the MW range and near diffraction-limited output beams, focussed intensities can exceed 1012W/cm2: sufficient for ablation of most solid materials or to saturate nonlinear optical interactions.