Optical Pulse Synthesis From Two Separate Femtosecond Lasers
R K. Shelton, L -. Ma, H C. Kapteyn, M M. Murnane, J L. Hall, Jun Ye
Two independent mode-locked femtosecond lasers are tightly synchronized and phase locked. The rms timing jitter between the lasers is 4.3 fs within a 160 Hz bandwidth. The rms noise of the beat frequency between the two optical combs is 140 mHz at 1s averaging time. Coherence between the two phase locked pulse trains is demonstrated via spectral interferometry and the second order field cross correlation. Auto-correlation measurement of the combined pulse reveals a coherently synthesized pulse that is narrower and with a larger amplitude than theoriginal ones from the two lasers. The work should lead to a wide-range of applications including novel ultrafast field generation, wide-range of applications including novel ultrafast field generation, wide bandwidth quantum coherent control, and precision optical frequency metrology.