Ultra-short pulse propagation in a lossy acousto-optic tunable filter (AOTF)

Abstract

In this paper, we study the transmission characteristics of an AOTF operating with ultra-short light pulses (2 ps). Initially, one considers the performance of the device, operating in the nonlinear regime without loss. It was observed that the effect of dispersion and nonlinearity has a strong influence on the pulse propagation when one increases the length of the AOTF. For a shorter length device, the switched pulse presents time broadening. For a higher length device, pulse break up was observed. Regarding the AOTF with loss, one considers a device of 0.25 mm length with a loss of 4 dB/mm constructed with an increasing nonlinearity profile. It was observe that the increase in β (increase of the final value of the profile Q(ξ) of the nonlinearity) changes the switched pulse from broadening to optical compression. One can say that the AOTF can be operated in a configuration that avoids pulse break up and has a switched pulse with a shorter time duration compared with the lossy AOTF. The study of the AOTF operating with ultra-short optical solitons provides possibilities for achieving high efficiency in ultra-fast all-optical signal processing, especially for optical switches, filters, and optical transistors. The acousto-optic tunable filter (AOTF) has attracted great attention in recent years, in part because it appears to be a suitable basis for multiwavelength 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 multiwavelength router. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 28: 346–350, 2001.