Proceedings of Topical Meeting on Optoinformatics (pdf-format, 1.21 ...

SAINT-PETERSBURG, October 17 – 20, 2005 65
GENERATION OF THE DISCRETE SPECTRAL
SUPERCONTINUUM IN TWO INTENSIVE ULTRASHORT PULSES
INTERACTION
M. A. Bakhtin, S. A. Kozlov
St.Petersburg State University <strong>of</strong> Information Technologies, Mechanics and Optics
Kronverksky pr. 49, St.Petersburg, 197101, Russia
E-mail: bakhtin@rain.ifmo.ru
It is shown that nonlinear interaction <strong>of</strong> two intensive few-cycle pulses in
waveguide can result in high repetition rate optical sequence generation with
quasi-discrete spectrum that can be used for information encoding.
The fiber optical systems have gained more and more popularity for data
transmission. Wave density multiplexing systems are widely used now to achieve high
bandwidths for optical channels. Current WDM implementations require many optical
sources (one for every channel). In present paper we consider a method <strong>of</strong> generation <strong>of</strong>
very high frequency optical signal sequence based on interaction <strong>of</strong> two few-cycle laser
pulses propagating collinearly in transparent nonlinear media with different group
velocities. The spectrum <strong>of</strong> generated sequence is quasi-discrete that allows using it as
multiple light sources with different wavelengths. Fig. 1 demonstrates the interaction <strong>of</strong> the
two few-cycle pulses with central wavelengths 780 nm and 390 nm with input intensities
2·10 13 W/cm 2 in fused silica.
Fig. 1. Spatial evolution <strong>of</strong> electric field envelope ε ( z , t ) for the pulses interaction with peak
input intensity I 1 =I 2 =2·10 13 W/cm 2
Fig. 2. Quasi-discrete spectrum <strong>of</strong> generated sequence
The interaction was modeled by nonlinear equations describing the temporal
evolution <strong>of</strong> light pulse electrical fields and their spatial - temporal spectra upon the pulses