Where Beam Paths and Career Paths Intersect

As laser safety officer (LSO), Hayden Johnson knows the location and handling protocols for hundreds of lasers across the Lawrence Livermore National Laboratory campus. He spends much of his time working with laser scientists to ensure that their equipment and operations are run in a safe manner.

Serving in this role is especially fulfilling because his responsibilities place him in direct conversation with scientists performing a broad range of research.

“When I go into the field and make laboratory visits, I aim to understand the methods and goals of each team's research project,” Johnson says. “That way, I can confirm whether the laser equipment present is the best choice for the anticipated experiments; otherwise, I help teams consider modifications or alternative procurements that would accomplish their goals and abide by safety standards.”

Johnson is responsible for cataloging and ensuring the safe operation of Class 3B and Class 4 lasers. At the lower end of this range, Class 3B lasers can easily cause eye injury without proper protection and can cause materials to heat and potentially catch fire if concentrated in the same spot for long enough.

Class 4 lasers require even greater safety precautions and include lasers all the way up to extremely powerful systems such as the National Ignition Facility (NIF) and the Jupiter Laser Facility (which are informally referred to as “Class 5”).

As an LSO, Johnson spends much of his time working with laser scientists to ensure that their equipment and operations are run in a safe manner. This often includes reviewing work control documents, performing audits of operations and investigating the precautions associated with laser equipment that research teams are considering purchasing for their work. He is also responsible for conducting operations training for new system users and investigating safety incidents in the event they occur.

Originally from Kentucky, Johnson first learned about LLNL through his university’s job fair while completing an M.S. in occupational safety and health. He then joined LLNL to work as an industrial safety professional in the Environment, Safety, and Health (ESH) organization.

“Hayden was brought on as an intern during COVID to build a laser inventory database,” says Jamie King, LLNL’s chief LSO. “His work and fascination with lasers was so impressive that I told him to take a job at the Lab, and I would get him into laser safety. We created a formal Laser Safety Office, and Hayden was the first person to join. He is an integral part of the office, providing logical solutions to our laser user community helping to get work done safely. Not much good came out of COVID, but we were fortunate to score Hayden.”

Now that Johnson has worked at LLNL for several years, Johnson knows more of the ropes and can impart knowledge to new hires and interns. He says this instruction and mentorship serves to bridge the gap between on-paper safety standards and real-life scenarios at LLNL.

Johnson's laser safety expertise was recently recognized when the International Laser Safety Conference, the discipline's pre-eminent conference, chose him to co-chair this year's Technical Practical Applications Seminar. He was tasked with defining session themes, selecting presenters and their desired topics and adjusting the event's offerings based on presenter availability for the day-and-a-half seminar.

When not discussing laser safety with colleagues and trainees, Johnson is enthusiastic when talking to young audiences about the sciences, and he is a staple of LLNL’s STEM outreach events. As student groups tour the NIF laser bay and are dwarfed by the immense size of the NIF beamlines, Johnson demonstrates the physics of lasers to students using his custom-built optical science setup.

Johnson explains how the light that lasers produce is monochromatic, collimated (parallel), and coherent, as opposed to light produced by the sun, which shines with many wavelengths and orientations. His Laser Application Demonstration then showcases key principles of laser light behavior and its applications: the patterns of constructive and destructive interference produced when passing light through a double slit, the patterns produced by diffraction gratings and interferometry techniques used to make microscopic measurements. These principles are at the heart of large laser systems like NIF, albeit at a grand scale.

True to the role of an LSO, Johnson also demonstrates the importance of laser safety considerations. “If I switch the beam path,” he says, rotating a few of the optics by hand, “now, the beam is traveling upward all the way to the ceiling.”

He then flips around a solid object to interrupt the beam's path, and the small red spot on the ceiling disappears. “Of course, this setup only uses a light source about as powerful as an office laser pointer, so no harm done. But imagine if it were powerful enough to injure someone or burn a hole through metal! You can see how precautions like beam blocking are so important to preventing injuries and damage to other equipment.”

Johnson says he is heartened by the interest shown by the students he gets to interact with.

“Kids who come to these events frequently ask very insightful questions,” he says. “Sometimes, I've had to pause and consider how to properly answer without getting too far into the weeds scientifically.”

He feels that outreach is critical to attracting and inspiring youth to pursue the sciences. “Science doesn't happen unless you get curious people involved, and I'm glad that I can play a part in spurring some of that involvement.”

More Information:

“LLNL Laser Experts Shine at Laser Safety Conference,” NIF & Photon Science News , June 10, 2025

“NIF Laser Safety Protocols Laid a Foundation for Historic LLNL Ignition Shot,” NIF & Photon Science News , June 7, 2023

“New Generation of Laser Safety Officers Convene for DOE Workshop,” NIF & Photon Science

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