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In this paper, we have spoken about how the superposition of two upper states and the quantum interference effect affect exchange efficiency in a V-type atomic system. We have demonstrated that the same orbital angular momentum can generate an additional signal field in response to a single optical vortex light acting on one transition of the V-type quantum system. We have also discussed about how the exchange efficiency of optical vorticity is affected by the quantum interference term, the probe’s detuning, and the superposition of the higher states. Our model is ideal for quantum information processing based on the orbital angular momentum of light due to the enhancement in exchange efficiency.

In this paper, we have discussed the spatial dependence of linear and nonlinear optical properties of infrared laser pulse in a single-layer graphene system. We have proposed two scenarios for adjusting the linear and nonlinear optical properties of the medium. In the first assumption, the graphene system interacts by an elliptical polarized optical vortex light and we adjust the linear and nonlinear properties via ellipticity and vorticity parameters. We found that the enhanced nonlinear coefficient was obtained with reduced linear absorption. In the second assumption, we assumed that two composite optical vortex lights interact with graphene layer. In this case the linear and nonlinear optical properties can be controlled via orbital angular momentum (OAM) of the applied lights. Here, we have shown that by adjusting the azimuthal angle of the composite vortex light, the spatial control of linear and nonlinear properties is possible. We found that in some regions of space the probe absorption vanishes and enhanced the nonlinear coefficient accompanied with optical transparency. Our results may be useful applications in future in all-optical system devices in nanostructures.

In this project, we have investigated the possibility of mimicking the natural photosynthesis, as well as sensing and adsorption application of aluminum decorated graphitic C

In this letter we have proposed a four-level graphene monolayer system for identifying the topological charge of Laguerre–Gaussian light. Here, we have shown that due to the four-wave mixing mechanism in the monolayer graphene system, a weak signal beam can be generated due to quantum coherence and interference effect. We have discussed the spatially dependent linear absorption spectrums of the weak probe and new generated signal beams via quantum mechanical density matrix formalism. We have found that by numbering the spot areas of the probe and signal beams, one can realize the topological charge of the Laguerre–Gaussian beam interacts by monolayer graphene system. Moreover, we have realized that for some topological charge the new generated signal beam can be amplified in the graphene system.

In this letter, we have studied the optical lateral shifts of transmitted and reflected lights in a defect structure doped by a single layer of graphene nanostructure. For adapting the optical features of the lateral shifts, we have first studied the refractive index properties of the defect layer. We have studied the conditions for achieving the negative and positive refractive index of the graphene monolayer system. After that, we have discussed the optical lateral shifts of the reflected and transmitted light beams when the refractive index of the graphene nanostructure become positive or negative, respectively. We have found that the enhanced lateral shifts for reflected and transmitted lights may be possible for a positive refractive index. For the negative refractive index, we have realized that simultaneous negative or positive lateral shifts are possible for the reflected and transmitted light beams. In our proposed scheme, the lateral shifts at the fixed incident angle are possible only by tuning the optical parameters without needing to change the cavity structure.

In this letter, we theoretical investigated electromagnetically induced phase grating in a three-level quantum system. The quantum system interacts with two weak probe and signal lights and a strong coupling light. We show that in two different parametric conditions i.e. in electromagnetically induced transparency (EIT) and Autler–Townes splitting (ATS) regimes, the probe and signal beams can be diffracted into the high-order directions. We realized that in the EIT regime, some of probe energy transfer from zero order to the high orders, while in ATS regime most of probe energy transfers to the high orders and small portion remain in the zero order.