Processing of telecommunication signals using periodically poled lithium niobate waveguides

Abstract

This talk reports on processing of high-speed telecommunication signals based on cascaded quadratic nonlinearities in periodically poled lithium niobate (PPLN) waveguides. A strong pump positioned within the acceptance bandwidth of the PPLN device can interact via a cascaded nonlinear process with a second signal, thereby facilitating a switch with a broad optical bandwidth and yielding an output located within the same wavelength band as the inputs. The combination of the PPLN switch with custom-designed optical filtering for pre-conditioning of the signals gives rise to a versatile pulse processing system exhibiting important advantages in terms of compactness and environmental stability. As an example, Fig.1 describes schematically how an optical time-division multiplexed (OTDM) signal can be converted through cascaded second-harmonic generation and difference-frequency generation to a wavelength-division multiplexed (WDM) signal. The experiments that have led to this demonstration will be described in the talk