Anshou Zheng

Generation of frequency entangled states via four-wave mixing in semiconductor well waveguide

We propose and analyze a scheme to realize a maximally frequency entangled state via four-wave mixing in semiconductor well waveguide. This scheme uses light hole transition to induce nonradiative quantum coherence in the waveguide. The results show that the transformation efficiency is perfect and the velocity of the entangled state is slow. By adjusting the intensity of strong controlling fields, the storing and retrieving process of the maximum entangled state can be achieved in our scheme.

Nonreciprocal light propagation in coupled microcavities system beyond weak-excitation approximation

We propose a scheme for nonreciprocal light propagation in two coupled cavities system, in which a two-level quantum emitter is coupled to one of the optical microcavities. For the case of parity-time (

Controlled switching of discrete solitons in periodically poled lithium niobate waveguide arrays

{\mathscr{P}}{\mathscr{T}}

Generalized analytical solutions and breather for nonlinear acoustic wave propagation in molecular magnets

PT) symmetric system (i.e., coupled active-passive cavities system), the cavity gain can significantly enhance the optical nonlinearity induced by the interaction between a quantum emitter and cavity field beyond weak-excitation approximation. The increased optical nonlinearity results in the non-lossy nonreciprocal light propagation with high isolation ratio in proper parameters range. In addition, our calculations show that nonreciprocal light propagation will not be affected by the unstable output field intensity caused by optical bistability, and we can even switch directions of nonreciprocal light propagation by appropriately adjusting the system parameters.

Multiple Waveguides Fabricated Simultaneously by Femtosecond Laser Pulses Inside Fused Silica Glasses Using a Multiple Foci Approach

Based on constructive interference in Sagnac waveguide loop, an efficient scheme is proposed for selective frequency conversion and multifrequency modes W entanglement via input–output formalism. We can adjust the probability amplitudes of output photons by choosing parameter values properly. The tunable probability amplitude will lead to the generation of output photon with a selectable frequency and W photonic entanglement of different frequencies modes in a wide range of parameter values. Our calculations show the present scheme is robust to the deviation of parameters and spontaneous decay.

SPIN-J GEOMETRIC PHASE DRIVEN BY A CLASSICAL FLUCTUATING FIELD

We suggest an effective method for controlling nonlinear switching in one-dimensional waveguide arrays formed by the periodically poled lithium niobate. We demonstrate that the ability of switching for discrete solitons is relative to the coupling coefficient that is determined by the applied external electrical field on periodically poled lithium niobate waveguide arrays. Besides the external electrical field, the switching of the discrete solitons is also determined by the excited beams tilted angle. It provides us an easy way to control the light beam propagation in such waveguide arrays based on electro-optical effects when an external electric field is applied.

Coherent laser-induced optical behaviors in three-coupled-quantum wells and their application to terahertz signal detection

In this paper, we propose an effective scheme to create a frequency entangled states based on bound-to-bound inter-subband transitions in an asymmetric three-coupled quantum well structure. A four-subband cascade configuration quantum well structure is illuminated with a pulsed probe field and two continuous wave control laser fields to generate a mixing field. By properly adjusting the frequency detunings and the intensity of coupling fields, the conversion efficiency can reach 100%. A maximum entangled state can be achieved by selecting a proper length of the sample. We also numerically investigate the propagation dynamics of the probe pulse and mixing pulse, the results show that two frequency components are able to exchange energy through a four-wave mixing process. Moreover, by considering special coupling fields, the storage and retrieval of the probe pulse is also numerically simulated.

Dynamic control of light propagation and optical switching through an RF-driven cascade-type atomic medium

In this paper, we show that, in the presence of two strong ac magnetic fields, a weak acoustic wave interacts with a crystal of molecular magnets. We obtain the analytical expression for absorption and group velocity in the linear case and discuss the effect of two coupling fields intensity on absorption and group velocity. Then, we find and analyze a series of generalized analytical solutions for nonlinear acoustic wave propagation in molecular magnets with arbitrary linear and nonlinear coefficients.