Science 2001 Aug;293(5533):1286-9
JILA (formerly Joint Institute for Laboratory Astrophysics), National Institute of Standards and Technology (NIST) and University of Colorado, Department of Physics, University of Colorado, Boulder, CO 80309-0440, USA.
We generated a coherently synthesized optical pulse from two independent mode-locked femtosecond lasers, providing a route to extend the coherent bandwidth available for ultrafast science. The two separate lasers (one centered at 760 nanometers wavelength, the other at 810 nanometers) are tightly synchronized and phase-locked. Coherence between the two lasers is demonstrated via spectral interferometry and second-order field cross-correlation. Measurements reveal a coherently synthesized pulse that has a temporally narrower second-order autocorrelation width and that exhibits a larger amplitude than the individual laser outputs. This work represents a new and flexible approach to the synthesis of coherent light.