Lasers & Sources

ILA team pushes applications envelope for phase-locked femtosecond lasers

May 1, 2003

If a laser pulse were made shorter than a single cycle of light, Maxwell's law says that it would no longer be able to propagate.

If a laser pulse were made shorter than a single cycle of light, Maxwell's law says that it would no longer be able to propagate. Jun Ye, a physicist at the National Institute of Standards and Technology (NIST; Boulder, CO) and a fellow of JILA at the University of Colorado in Boulder, and his fellow researchers consider generating a nonpropagating optical pulse, as well as disobeying Oppenheimer's approximation—that molecular nuclei must remain bound in electronic potential wells—among the more challenging yet achievable goals for their perfectly synchronized and phase-locked femtosecond laser pairs.

Researchers (from left) Jason Jones, David Jones, Seth Forman, and Kevin Holman look over the setup that generates synchronized, phase-locked femtosecond laser pulses.

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Their most recent publication describes an optical atomic clock that is linked to a 1550-nm modelocked laser diode with ultralow timing jitter that could ultimately provide the basis of a GPS-style timing system, distributed over an optical-fiber network, however, instead of through free space, Ye said (see figure).¹ Other published work describes the flexible generation of tunable, subpicosecond pulses in the infrared spectral range and the achievement of significant improvements in experimental sensitivity and spatial resolution for coherent anti-Stokes Raman scattering (CARS) microscopy.^{2, 3}

All of this proposed and current work is based on their successful merger two-years ago of beams from two independent, ultrafast lasers into one train of synthesized pulses with shorter time duration and larger amplitude than those created by either laser individually (see Laser Focus World, November 2001, p. 30).⁴

REFERENCES

D. J. Jones, K. W. Holman, M. Notcutt et al, Optics Lett. 28(10) (May 15, 2003).
S. M. Foreman, D. J. Jones, J. Ye Optics Lett. 28(5) 370 (March 1, 2003).
D. J. Jones, E. O. Potma, J.-X. Cheng et al, Rev. Scient. Instrum. 73(8) 2843 (August 2002).
R. K. Shelton, L.-S. Ma, H. C. Kapteyn et al, Science 293, 1286 (Aug. 17, 2001).