James Kafka

James Kafka (January 27, 1956) is an American physicist and inventor in optics. He is an Emeritus Fellow at MKS Instruments and Spectra-Physics Lasers, where he has designed picosecond lasers and femtosecond lasers.

Kafka served as the President of Optica in 2025.

Research and career At Spectra-Physics, Kafka designed various lasers for use in industrial and research applications, including physical chemistry, high energy physics, optoelectronics, and related fields in optics. His inventions include a high-power mode-locked laser system, a high-power ytterbium-doped calcium fluoride laser system, and a regenerative amplifier system, among other laser technologies. An example of the Spectra Physics Tsunami, developed in 1990. The bright red light on the left is the Ti:sapphire crystal; the bright green light is scattered pump light from a mirror. The image was taken at Lund University (Sweden), October 2004. In 1990, Kafka introduced the Tsunami, the first commercial ultrafast Ti: sapphire laser, which allows for spectral outputs ranging from ultra-narrow single frequencies to wide bandwidths over several hundred nanometers.

In 1997, Kafka designed the first diode-pumped double-clad fiber laser, consisting of a single-mode optical fiber core that is pumped by a high-power coherent laser diode source.

Additionally, Kafka developed the first commercial 10W solid-state green laser in 1997 and the first broadly tunable ultrafast source for microscopy in 2011. His contributions to the professional association include a tenure as the Ultrafast Topical Editor for the Journal of the Optical Society of America from 1994 to 1995, service as a co-chair for the Conference on Laser and Electro-Optics and Advanced Solid-State Photonics conferences, and lecturer at student-focused events.

Volunteer work Kafka volunteers with various academic and industrial institutions to deliver public lectures and engage with students and faculty to advocate for education in laser science.

His engagement activities include supporting events such as the University of Central Florida College of Optics and Photonics Industrial Affiliates Symposium, the Stanford University Photonics Retreat, the Siegman International School on Lasers. 2005: Optica Fellow

Selected publications Simon Lefrançois, Khanh Kieu, Yujun Deng, James D. Kafka, and Frank W. Wise, "Scaling of dissipative soliton fiber lasers to megawatt peak powers by use of large-area photonic crystal fiber," Opt. Lett. 35, 1569-1571 (2010). https://doi.org/10.1364/OL.35.001569

Klein, J., Kafka, J. The flexible research tool. Nature Photon 4, 289 (2010). https://doi.org/10.1038/nphoton.2010.108

J. D. Kafka and T. M. Baer, "Peak power fluctuations in optical pulse compression," in IEEE Journal of Quantum Electronics, vol. 24, no. 2, pp. 341–350, Feb. 1988, doi:10.1109/3.131.