ABSTRACT
We report for the first time acousto-optical transmission resonances in a non-silica fiber. The resonances, generated in highly nonlinear, single-mode Chalcogenide (As2Se3) fiber, are up to -9 dB deep and tunable over 235 nm around 1450 nm by varying the frequency of an acoustic wave propagating in the fiber, creating a variable period long period grating. The material properties of Chalcogenide modify the acoustic wave propagation leading to a different frequency range of operation when compared to Silica fiber. A tunable resonant structure in this medium opens up possibilities for all-optical processing and mid-IR applications.
ABSTRACT
This paper presents an all-optical, in-band optical signal-to-noise ratio (OSNR) and chromatic dispersion monitor. We demonstrate monitoring over the 1 nm bandwidth of our signal, which is a 10 GHz pulse train of 8.8 ps pulses. The monitor output power, as measured on a slow detector, has a 1.9 dB dynamic range when the signal OSNR is varied by 20 dB, and a 1.6 dB dynamic range when +/- 150 ps/nm of chromatic dispersion is applied. Cascaded four-wave mixing occurring in the optical parametric amplifier provides the nonlinear power transfer function responsible for the monitoring. An analysis using the signals' probability density functions show that the nonlinear power transfer function provides preferential gain to clean undispersed pulses when compared to noisy and/or dispersed pulses. Our analysis includes a consideration of the applicability of the device to high duty cycle systems, and simulations on monitoring of a 40 Gb/s pulse train with a 50% duty cycle.
