The Ohio State University

GRAY Laser

GRAY femtosecond laser system in operation

GRAY is a high average power femtosecond laser system designed to deliver short pulses from 200 nm – 10,000 nm wavelengths, and pulse widths from 5 fs – 400 ps, when fully completed. Designed and Constructed in house, at present, GRAY delivers 3 mJ/pulse @ 1 kHz repetition rate, and has a 1.3 micron and a 2.0 micron short pulse OPA arm.  The 3 – 5 micron OPA arm is currently under construction.

GRAY laser is supported by AFOSR


image003FSD Lab recently completed construction of a <6 fs arm with over 300 nm bandwidth. Energy/pulse can be varied from 0.4 – 1.5 mJ. This new capability will allow us to probe solid dynamics with much finer time resolution. In collaboration with Femtolasers, Gmbh.


GRainbow spectrum after pulse is dispersed by a diffraction grating


GRainbow uses non-linear mixing in hollow core fiber to generate upto an octave spanning spectrum with high efficiency

FROG (Frequency Resolved Optical Gating) of few cycle pulses, for full electric field reconstruction

EMIR (Extreme Mid IR) Optical Parametric Amplifier Laser:

Extreme Mid IR OPA

Extreme Mid IR OPA focus laser-writing its name on a Silicon wafer.

EMIR is a KNbO3 based OPA to reach from 2800 – 4500 nm with a high quality mode, capable of delivering 10 J/cm2 fluences on target. With a pulse-width of 180 femtosecond, EMIR is used to study non-linear optics in the Mid IR regime, femtosecond laser damage, and band structure dynamics.

Other Lasers:


PUPIL, an ultrashort pulse oscillator operating at 1550 nm, at 80 MHz repetition rate

PUPIL, an ultrashort pulse oscillator operating at 1550 nm, at 70 MHz repetition rate

We recently completed construction of PUPIL (Portable Ultrashort Pulse Intense Laser), a portable erbium doped fiber laser oscillator operating at 70 MHz repetition rate with a center wavelength of 1550 nm, and pulsewidth of ~200 fs. This laser is designed to be moved to different labs and incorporate with immovable UHV systems for femtosecond pump probe experiments.

PUPIL construction was supported by AFOSR. We are also grateful to Battelle ( for help with splicing fibers for the oscillator.

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