D. Taverner

158-microJ pulses from a single-transverse-mode, large-mode-area erbium-doped fiber amplifier.

We report the amplification of 10-100-pJ semiconductor diode pulses to an energy of 158 microJ and peak powers >100 kW in a multistage fiber amplifier chain based on a single-mode, large-mode-area erbium-doped amplifier design. To our knowledge these results represent the highest single-mode pulse energy extracted from any doped-fiber system.

Nonlinear self-switching and multiple gap-soliton formation in a fiber Bragg grating.

We report, for the first time to our knowledge, the experimental observation of quasi-cw nonlinear switching and multiple gap-soliton formation within the bandgap of a fiber Bragg grating. As many as five gap solitons with 100-500-ps durations were generated from a 2-ns pulse at a launched peak intensity of approximately 27 GW/cm(2). A corresponding increase in the grating transmission from 3% to 40% of the incident pulse energy was observed.

All-optical and gate based on coupled gap-soliton formation in a fiber Bragg grating

We experimentally demonstrate an all-optical AND gate based on coupled gap-soliton formation in an apodized fiber Bragg grating. A switching contrast of better than 17 dB is obtained with an incident pulse peak power of 2.5 kW.

Highly efficient second-harmonic and sum-frequency generation of nanosecond pulses in a cascaded erbium-doped fiber:periodically poled lithium niobate source.

By combining erbium-doped fiber sources based on a large mode-area design and periodically poled lithium niobate, we have obtained single-pass conversion efficiencies of as much as 83% (energy efficiency) for second-harmonic generation into the near IR (768 nm) and of 34% for sum-frequency generation into the green (512 nm) for nanosecond pulses, using first-order quasi-phase matching. Pulse energies in excess of 80microJ of second harmonic have been obtained from systems pumped by a single laser diode.

Experimental demonstration of intermodal dispersion in a two-core optical fibre

Abstract The recent prediction that intermodal dispersion could affect the propagation of short pulses in a two-core optical fibre was confirmed experimentally. A picosecond pulse at 1.548 μm launched into one core of a meters-long two-core fibre was found to come out of either core of the fibre as two temporally separate pulses. By measuring the time delay between these two pulses, the intermodal dispersion in the fibre was estimated to be 1.13 ps/m, in good agreement with theory.

Optical parametric oscillation in periodically poled lithium niobate driven by a diode-pumped Q-switched erbium fiber laser.

We describe what is to our knowledge the first nanosecond periodically poled lithium niobate (PPLN) optical parametric oscillator (OPO) driven by a fiber laser. The source was frequency doubled by a PPLN sample before pumping a second, 20-mm-long, PPLN crystal. The OPO threshold was <10muJ, with pump depletions of as much as 45% and a tunable signal range of 945-1450 nm (1690-4450-nm idler range). We demonstrated 130-nm signal tuning by varying the pump wavelength and doubling crystals temperature. Also, we achieved 15-nm tuning with all crystals at a constant temperature. The results demonstrate the potential of the fiber laser:PPLN combination for practical, versatile, and tunable sources.

HIGH-POWER CHIRPED-PULSE ALL-FIBER AMPLIFICATION SYSTEM BASED ON LARGE-MODE-AREA FIBER GRATINGS

We describe the fabrication of chirped gratings in a specially developed photosensitive large-mode-area fiber and report the use of these components in a picosecond all-fiber chirped-pulse-amplification circuit. We demonstrate the generation of microjoule energy pulses with peak powers in excess of 500 kW, which we believe to be a record peak power from an all-fiber system.

Nonlinear switching in fibre Bragg gratings.

We report on our recent experiments on nonlinear switching in fibre Bragg gratings. Using an all-fibre source we show an increase in transmission of a FBG from 4% to 40% at high powers. This switching is associated with the formation of gap solitons inside the grating. We also demonstrate an all-optical AND gate using polarization coupled gap solitons and the optical pushbroom.

Experimental observation of nonlinear pulse compression in nonuniform Bragg gratings

We demonstrate a scheme for optical pulse compression by cross-phase modulation that utilizes a nonuniform Bragg grating to work in reflection. Our scheme is similar to the conventional optical pushbroom, which works in transmission. This reflection geometry has the advantage of allowing the compressed signal to be observed easily, as it is spatially separate from the pump. This is to our knowledge the first nonlinear effect to be observed that requires a nonuniform grating.

Transmission of 6 ps linear pulses over 50 km of standard fiber using midpoint spectral inversion to eliminate dispersion

Transmission of 6 ps linear pulse pairs over 50 km of standard fiber is demonstrated by employing midpoint spectral inversion (phase conjugation) of the data signal to compensate dispersion effects. Pulse broadening as low as 10 percent and faithful reconstruction of the pulse patterns are observed and confirm the applicability of this technique to bit rates greater than 100 Gb/sup -1/. >