We demonstrate passive generation of optical pulse trains with each pulse having distinct center carrier and spectra using tunable group delay (GD) staircase transfer functions. The GD steps result from opposite and equal magnitude GD slopes from narrowband and wideband tunable optical dispersion compensators. We use this technique to split the spectrum of a femtosecond pulse to a pulse burst with precise control of pulse time separation. © 2012 Optical Society of America

We demonstrate high resolution and increased efficiency background-free time-to-space conversion using spectrally resolved non-degenerate and collinear SFG in a bulk PPLN crystal. A serial-to-parallel resolution factor of 95 and a time window of 42 ps were achieved. A 60 fold increase in conversion efficiency slope compared with our previous work using a BBO crystal [D. Shayovitz and D. M. Marom, Opt. Lett. 36, 1957 (2011)] was recorded. Finally the measured 40 GHz narrow linewidth of the output SFG signal implies the possibility to extract phase information by employing coherent detection techniques. ©2012 Optical Society of America

An optimization procedure for spatial mode multiplexing from individual single-mode fibers into a three-mode fiber based on a spatial aperture sampling concept has been developed. By placing space-variant imaging elements between the single-mode and few-mode fibers, each beam aperture can be shaped for lower loss coupling and low mode-dependent losses. The optimization achieves a record theoretical -1.5-dB insertion loss, improving on the previous theoretical -2-dB record.