PICOSECOND PULSE SWITCHING IN AN ACOUSTO-OPTIC TUNABLE FILTER (AOTF) WITH LOSS

Abstract

In this paper, we did a study of the transmission characteristics of the AOTF operating with ultrashort light pulses <$>(2\,\hbox{ps})<$>. Initially one considers the performance of the device, with several lengths, operating in the nonlinear regime without loss. It was observed that the effect of dispersion and non-linearity has strong influence on the pulse propagation when one increases the length of the AOTF. For shorter length of the device the switched pulse is presenting time broadening for soliton and non-soliton profiles. For higher length of the device, pulse breakup was observed for the non-soliton profile and time displacement for the soliton profile. Considering the device of length <$>0.25\,\hbox{mm}<$> with <$>4\,\hbox{dB/mm}<$> of loss and constructed with an increasing non-linearity profile, one can say that one can operate the AOTF in a configuration that one can avoid the pulse break up and have a switched pulse with a shorter time duration compared with the lossy AOTF. The study of the AOTF operating with ultra short optical pulses provides possibilities for achieving, high efficiency in ultrafast all-optical signal processing, especially for optical switches, filters and optical transistors. The acoustic-optic tunable filter (AOTF) has attracted great attention in recent years, in part because it appears to be a suitable basis for multi-wavelength optical cross-connects. It is probably the only known tunable filter that is capable of selecting several wavelengths simultaneously. This capability can be used to construct a multi-wavelength router.