
I found our cover story on photobiomodulation (PBM) therapy—a technique for healing brain injuries and disease with light—to be one of the most compelling articles we've ever published. I think you will, too. The article is written by Barbara Gefvert, editor-in-chief of our BioOptics World section (see page 31), and tells the story of how research and trials with PBM therapy are proving that laser or LED light can aid victims of traumatic brain injury (TBI) and more. The possibilities extend from head injuries sustained in combat or accidents to post-traumatic stress disorder and neurodegenerative diseases such as Alzheimer's.
Photobiomodulation is earning its place in bioscience and medicine alongside photonics technologies such as microscopy, imaging, optogenetics, and optical coherence tomography (OCT). And the importance of related optical test and measurement techniques extends beyond the brain: OCT itself relies on critical light source calibration for accurate depth readings, as described in an article this issue from Marcus Duelk at Exalos (see page 45). An article by Albrecht Bartels and Thomas Dekorsy at Laser Quantum describes an ultrafast sampling oscilloscope that measures at femtosecond time scales (see page 36). And laser interferometry is used to provide feedback for industrial machine positioning, as explained in an article by William Land II at Aerotech (see page 55).
None of these can match the cosmic measurement scale and precision of the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the recent astounding detection of cosmic gravitational waves. In separate interviews, Robert Byer at Stanford University (see page 23) and Yong Zhang at Access Laser (see page 72) both show how different photonics technologies are playing such critical roles in the success of LIGO. Perhaps the leap from brain science to detecting ripples in the fabric of spacetime is really not so far.

Conard Holton
Conard Holton has 25 years of science and technology editing and writing experience. He was formerly a staff member and consultant for government agencies such as the New York State Energy Research and Development Authority and the International Atomic Energy Agency, and engineering companies such as Bechtel. He joined Laser Focus World in 1997 as senior editor, becoming editor in chief of WDM Solutions, which he founded in 1999. In 2003 he joined Vision Systems Design as editor in chief, while continuing as contributing editor at Laser Focus World. Conard became editor in chief of Laser Focus World in August 2011, a role in which he served through August 2018. He then served as Editor at Large for Laser Focus World and Co-Chair of the Lasers & Photonics Marketplace Seminar from August 2018 through January 2022. He received his B.A. from the University of Pennsylvania, with additional studies at the Colorado School of Mines and Medill School of Journalism at Northwestern University.