HAPLS has set a world record for diode-pumped petawatt lasers, with energy reaching 16 joules and a 28 femtosecond pulse duration (equivalent to ~0.5 petawatt/pulse) at a 3.3 hertz repetition rate (3.3 times per second). Credit: Lawrence Livemore National Laboratory

The continuous operation of an all diode-pumped, high-energy femtosecond petawatt laser system has been demonstrated.

The High-Repetition-Rate Advanced Petawatt Laser System (HAPLS) developed at the Lawrence Livemore National Laboratory is officially ready for delivery and integration at the European Extreme Light Infrastructure Beamlines facility project in the Czech Republic.

The laser system set a world record for diode-pumped petawatt lasers, with energy reaching 16 joules (J) and a 28 femtosecond pulse duration at a 3.3 hertz repetition rate.

LLNL Director Bill Goldstein explained the achievement.

“Lawrence Livermore takes pride in pushing science and technology to regimes never achieved before,” Goldstein said in a statement. “Twenty years ago, LLNL pioneered the first petawatt laser, the NOVA Petawatt, representing a quantum leap forward in peak power.

“Today, HAPLS leads a new generation of petawatt lasers, with capabilities not seen before.”

Petawatt peak power pulses focus a high intensity on a target and generate secondary sources, including electromagnetic radiation or accelerate charged particles.

This enables unparalleled access to a variety of research areas, including time-resolved proton and X-ray radiography, laboratory astrophysics and other basic science and medical applications for cancer treatments, in addition to national security applications and industrial processes, including nondestructive evaluation of materials and laser fusion.

Until now proof-of-principle experiments with single-shot lasers have provided a small glimpse into this arena of transformation applications. A high-repetition-rate petawatt laser is needed to commercially explore these areas.

Constantin Haefner, LLNL's program director for Advanced Photon Technologies (APT), said the laser system will enable major advancements.

“The high-repetition-rate of the HAPLS system is a watershed moment for the community,” Haefner said in a statement. “HAPLS is the first petawatt laser to truly provide application-enabling repetition rates.”

In the last three years HAPLS went from a concept to a fully integrated and record-breaking product.

Since high-power lasers were introduced decades ago, they have illuminated entirely new fields of scientific endeavor, in addition to making profound impacts on society.

The research team drew on decades of laser research and development advancements that led to the key advancements that distinguish HAPLS form other petawatt lasers.

HAPLS has the ability to reach petawatt power levels while maintaining an unprecedented pulse rate. HAPLS also has the world’s highest peak power diode arrays, driven by a Livemore-developed pulses power system, a pump laser generating up to 200 J at a 10 Hz repetition rate, a gas-cooled short-pulse titanium-doped sapphire amplifier, a sophisticated control system with a high level of automation including auto-alignment capability, fast laser startup, performance tracking and machine safety, dual chirped-pulse-amplification high-contrast short-pulse front end and a gigashot laser pump source for pumping the short-pulse preamplifiers.

Roman Hvezda, ELI Beamlines project manager, explained why ELI Beamlines went with the Livemore project.

“It was quite straightforward,” Hvezda said in a statement. “Given the design requirements, nobody else could deliver this system in such a short time on schedule and on budget.

“It's a great benefit to be able to cooperate with Livermore, a well-established lab, and this will be a basis for continued cooperation in the future.”

Haefner added that the project was a partnership between the LLNL and the ELI Beamlines scientists and engineers.

“One of the real successes of this endeavor was that very early on, the client was fully integrated into the commissioning and operation of this laser,” Haefner said. “This provided hands-on training and expertise right out of the gate, helping to ensure operational success once the laser is installed at ELI Beamlines.

“We look at this as a long-term and enduring partnership.”

HAPLS will now be transferred to ELI Beamlines in the coming months, where it will be integrated into the facility’s laser beam transport and control systems and then brought up to full design specification.

HAPLS is expected to be available by 2018 to international science users to conduct the first experiments using the laser.

“HAPLS was a very fast-paced project," Haefner said. “In only three years it pushed the cutting edge in high-power short-pulse lasers more than tenfold, incorporating a completely new system approach.

“To do so, Livermore worked closely with industry to similarly advance the state of the art and many of those joint Livermore/industry innovations are already on the market,” he added. “These partnerships can be incredibly synergistic, resulting in successful and societal impactful technologies like HAPLS.”

HAPLS could enable a new generation of diode-pumped, high energy and high-peak-power laser systems with innovative technologies originating from the U.S. Department of Energy’s fusion laser research and development.