Alan B. Petersen

High-power TEM 00 -mode operation of diode-pumped solid state lasers

The performance of end-pumped YAG and YVO4 lasers in fundamental mode operation (M2 < 1.1) is reviewed and the physical limits of TEM00 output power is discussed. By using special resonator configurations, end-pumped lasers can be designed to provide high-power, excellent beam quality, and high-efficiency in spite of the large phase distortions commensurate with the strong aberrated thermal focusing. A 35 W infrared Nd:YVO4 laser was developed with a quantum efficiency of 94%, defined as a percentage of 1064 nm photons generated per quantity of absorbed 809 nm pump photon. A Q-switched end-pumped Nd:YAG laser provides an average output power greater 15 W in a polarized TEM00 mode with 29% optical efficiency at 1064 nm. External frequency doubling and tripling of this laser resulted in maximum output powers of 8.8 W and 4.2 W, respectively.

Second harmonic operation of diode-pumped Rb vapor lasers

A CW diode-pumped alkali laser (DPAL) based on the D1 rubidium resonance transition has been investigated. The pump sources for these experiments are two 780 nm fiber-coupled diode modules, incorporating volume holographic gratings for wavelength control. Total pump power is up to 64 W. Rb laser output at the 794.8 nm fundamental wavelength is up to 7.8 W. Intracavity second harmonic generation in BIBO generates up to 250 mW at 397.4 nm.

High-energy high-peak-power diode-pumped solid state laser for materials processing

The emergence of commercially available diode pumped solid state lasers in the 3-10 watt power range has created alternative laser sources for many light industrial applications. Laser marking, micro-machining, resistor trimming, disk texturing, and rapid prototyping are some of the applications which can benefit from this technology. In this paper, we describe fiber-coupled diode bar pumped Nd:YAG and Nd:YVO4 lasers with short pulse, high energy, and relatively high average power developed for these applications. Our design emphasizes system efficiency and simplicity to minimize the cost of ownership. The excellent beam spatial quality and pulse-to-pulse stability of these devices results in improved process yields for the end user.

Tunable, High Power, Narrow Band Emission from a Volume Grating-Controlled Diode Bar

A single laser diode bar generates over 50W output at 780 nm, with linewidth 0.1 nm. The diode emission wavelength is controlled by a volume transmission grating and is tunable over ≥ 0.4 nm.

A high-power, diode-pumped 355-nm laser system for micromachining applications

Summary form only given. Diode-pumped, Q-switched, solid-state lasers are rapidly becoming the preferred laser source in micromachining applications where their high efficiency, reliability, and excellent beam characteristics are important. We have developed a diode-pumped, Q-switched Nd:YAG laser as a replacement for the lamp-pumped devices found in many industrial systems.

Harmonic generation at high repetition rate with Q-switched Nd:YVO4 lasers

A variety of applications require short, energetic laser pulses delivered at high repetition rate. These include micro-machining, range finding, and scientific applications such as amplifier pumping. An important advantage provided by diode-end-pumping of solid state lasers is that this type of geometry allows the generation of short, energetic, Q-switched pulses at high repetition rate. The high peak power of such pulses facilitates harmonic generation. In this paper, we describe a high average power, high repetition rate Q-switched Nd:YVO4 laser, pumped by a fiber-coupled diode bar. The laser provides pulses of excellent spatial quality at repetition rates up to 100 kHz, average power 3-4 W, and durations of 8 to 20 nsec. The near-diffraction-limited beam and the high peak power allow efficient harmonic generation at high repetition rates. Second harmonic generation is achieved in non- critically-phase-matched LBO with a conversion efficiency of 55% at 20 kHz, providing an average power of 1.75 W at 532 nm. third harmonic generations (to 355) in LBO has been achieved with > 20% efficiency, resulting in an ultraviolet average power of 0.65 W at 20 kHz.

Laser Heated Pedestal Growth of Potassium Lithium Niobate for UV Generation

Potassium lithium niobate (KLN), a nonlinear optical material with high nonlinearity and other desirable properties, has the potential to improve the performance and reduce the cost of blue and UV lasers. KLN crystals have not entered the commercial mainstream because it is impossible to grow them reproducibly by conventional techniques. We have developed a proprietary process based on the laser heated pedestal growth (LHPG) technique that eliminates technical barriers to manufacturing KLN crystals. This paper describes the LHPG method of KLN crystal growth including improvements in crystal uniformity and transparency, and our latest harmonic generation results in the UV.

CW 795 nm Rb Vapor Laser Pumped by Volume Transmission Grating-Stabilized Diode Bar

We have constructed an atomic Rb vapor laser, operating at 795 nm. The laser is optically pumped by a fiber-coupled CW laser diode bar, wavelength-controlled at the 780 nm Rb absorption using a volume transmission grating. CW output from the Rb laser is 260 mW.

High energy, high peak power diode pumped solid state lasers for materials processing

The emergence of commercially available diode pumped solid state lasers in the 3 - 10 watt power range has created alternative laser sources for many light industrial applications. Laser marking, micro-machining, resistor trimming, disk texturing, and rapid prototyping are some of the applications which can benefit from this technology. In this paper, we describe fiber-coupled diode bar pumped Nd:YAG and Nd:YVO4 lasers with short pulse (< 10 ns), high energy (~ 2 mJ), and relatively high average power (3 - 10 W) developed for these applications. Our design emphasizes system efficiency and simplicity to minimize the cost of ownership. The excellent beam spatial quality and pulse-to-pulse stability of these devices results in improved process yields for the end user.The emergence of commercially available diode pumped solid state lasers in the 3 - 10 watt power range has created alternative laser sources for many light industrial applications. Laser marking, micro-machining, resistor trimming, disk texturing, and rapid prototyping are some of the applications which can benefit from this technology. In this paper, we describe fiber-coupled diode bar pumped Nd:YAG and Nd:YVO4 lasers with short pulse (< 10 ns), high energy (~ 2 mJ), and relatively high average power (3 - 10 W) developed for these applications. Our design emphasizes system efficiency and simplicity to minimize the cost of ownership. The excellent beam spatial quality and pulse-to-pulse stability of these devices results in improved process yields for the end user.