Sharif Digital Repository

In this paper, a new all optical phase-locked loop (OPLL) is proposed and analyzed. The scheme relies on using two optical Kerr shutters to reveal the OPLL's error signal. The set of optical Kerr shutters and the subsequent low-speed photodetectors realize two nonlinear cross-correlations between the local clock pulse stream (called pump in Kerr shutter notations) and the time-shifted replicas of the incoming received data signal (called probe). The outputs of the cross-correlators are subtracted to form the error signal of the OPLL. We characterize the mathematical structure of the proposed OPLL and identify its two intrinsic sources of phase noise, namely, randomness of the received... 

Frequency shift of the spectrum of an incident optical pulse by an intense THz pulse inducing cross-phase modulation (XPM) in a nonlinear dielectric slab is analyzed. The effect is predicted with a high degree of accuracy using the well-known transmission line matrix (TLM) technique. In this research, to model the THz-induced temporal and spatial variation of the dielectric permittivity of the nonlinear dielectric slab, the transmission lines of the TLM method are loaded with open shunt stubs. The parameters of the stubs are modified in accordance with the refractive index variation of the dielectric slab, here ZnTe, induced by the strong THz pulse. The obtained numerical results are...