This past summer, the ZEUS (Zettawatt Equivalence Ultrashort Pulse Laser System) laser facility at U of M blasted a laser beam with a power of 2 petawatts, a power 100 times greater than the world’s power output. ZEUS quadrupled the power output of its predecessor HERCULES, a laser which once held the world record for most intense laser at terawatts. According to UM researchers, the facility has plans to blow past this level and increase the power to 3 petawatts this fall, opening up new pathways to study particles and materials at the smallest and highest-energy levels.

“This laser will have the highest peak power in the United States and will be among the world’s most powerful laser systems for the next decade,” said Karl Krushelnick, the director of the Gérard Mourou Center for Ultrafast Optical Science at U-M, told U-M reporters.

The ZEUS facility will increase Michigan’s standings as a hub for discovery in physics. Funded by the National Science Foundation, ZEUS is a user facility, meaning that scientists around the country and the world can apply to use the laser for their own experiments.

Enlightening discoveries.

The ZEUS laser works using the same fundamental principles that drive all lasers since their invention in the 1960s. A photon of light is sent through a collection of atoms, and the atoms become energized. These atoms then release an additional photon with the same frequency as the first photon. The new photons might be bounced back through the atoms using mirrors, and generate more identical photons from the energized atoms, getting more powerful each time. Once the power is high enough, the atoms are released in a high-energy beam. While a household flashlight might have a beam with a wide diameter and a range of light frequencies, lasers have small beam diameters and a single light frequency, allowing a precise transfer of energy to target materials.

This process gave lasers their name: Light Amplification by Stimulated Emission of Radiation. A laser comes in two types: a continuous laser, and a pulsed laser. ZEUS is a pulse laser, which means the burst of energy comes in a discrete packet with a tiny length of time, like a wave coming to shore on a beach. ZEUS’s pulses last only 25 femptoseconds, or one quadrillionth of a second.

The first experiment using ZEUS aims to understand what happens to a beam of electrons when it collides with the 2 petawatt laser. The scientists aim to simulate a higher-powered laser by having the beam of electrons travel in the opposite direction as the beam of photons. The photons hit the electrons with a power on the order of zettawatts, or one sextillion watts, in the electrons’ frame of reference, like a bug hitting the windshield of a car. The experiment is set to run later this year.

Additionally, these high-energy, short-lived pulses can help scientists explore space. ZEUS can be used to study how particles behave in high electromagnetic field environments, such as in the jets of energy spewed out by black holes or in highly magnetized stars.

Lasers assisting cancer treatment.

According to the University of Michigan, research out of ZEUS can also be used to help accelerate particles to high speeds formerly only achieved by particle accelerators. Without the need for a particle accelerator, cancer patients could receive proton therapy instead of radiation therapy. Protons are less harmful than radiation because they destroy cancer while minimizing damage to the surrounding tissue.

ZEUS ranks among the most powerful lasers in the world, but the US falls short of two 10-petawatt lasers in Europe and a 5.3-petawatt laser in China, which could become a 100-petawatt laser in the future.