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We propose a new method for suppressing the timing jitters of soliton pulses by using periodic phase conjugations and optical spectral filters in a high bit-rate transmission system. It is proven that the tolerable transmission distance limited by timing jitters can be increased through modulating frequency shifts by optical phase conjugators and eliminating the interaction between dispersive waves and the central pulses by optical filters. Our results also show that the optical-phase-conjugated soliton with spectral filters is superior to the common soliton in suppressing polarization mode dispersion induced by random birefringence. The physical mechanisms of soliton timing jitters are analyzed.

We propose a design of narrow-band multi-channel optical filter using multiple stacks of unit cell consisting of trilayer of Doubly positive medium (DPS)–Doubly negative medium (DNG)–Epsilon negative medium (ENG). Finite Difference Time Domain (FDTD) technique is used to numerically simulate the effect of optical thickness of DPS, DNG and ENG media on tunability of the transmission spectrum of such a medium. We also demonstrate the control on the number of channels at different frequencies that can be transmitted through such medium.

Quantum memory is an essential tool for quantum communications systems and quantum computers. An important category of quantum memory, called optically controlled quantum memory, uses a strong classical beam to control the storage and re-emission of a single-photon signal through an atomic ensemble. In this type of memory, the residual light from the strong classical control beam can cause severe noise and degrade the system performance significantly. Efficiently suppressing this noise is a requirement for the successful implementation of optically controlled quantum memories. In this paper, we briefly introduce the latest and most common approaches to quantum memory and review the various noise-reduction techniques used in implementing them.

The properties of nonlinear optical (NLO) are examined, and the results confirm the 2.19eV HOMO–LUMO mismatch. In the AlPc cluster, certain functional bond lengths and bond angles have been observed. Quantum chemical methods (density functional theory (DFT) and time-dependent density functional theory (TD-DFT)) and vibrational spectra properties of AlPc are studied. An X-ray pattern reveals the crystalline structure along the (242) orientation of AlPc organic thin layer. An ultraviolet-visible (UV–Vis) also shows the frequency selective behavior of the device. The absorbance of such layer exhibits a high value within UV range and two consecutive peaks within the visible range. Spin coating is used to make an organic diode based on the Aluminium phthalocyanine (AlPc-Cl) molecule. Under dark and light conditions, electrical characterization of Ag/AlPc/Si/Au is obtained. The diode’s high rectifying capability (about $1\times 10^4)$ is subsequently discovered. While the height barrier is constant and saturation current is greatly reliant on light, the ideality factor of such a diode increases to 6.9 which confirms the nonideality of such a device. The Cheung–Cheung technique is employed to further the investigation and gain additional data such as series resistance and barrier height.

Global reactivity descriptors, Milliken’s charge distribution and molecular electrostatic potential based on Density Functional Theory (DFT), are used to understand the relationship between structure, stability and global chemical reactivity. In addition, these descriptors are used in the development of quantitative structure-activity and structure-property relationships. The study also shows the intense effect of the chlorine atom in the charge distribution. X-ray pattern reveals the crystalline structure along the (242) orientation of Aluminum Chloride phthalocyanine (AlCl-Pc) organic thin layer. Absorbance of such layer exhibits a high value within UV range and two consecutive peaks within visible range, spin coating is used to make an organic diode based on the AlCl-Pc cluster and the diode high rectifying facility is discovered. The height barrier is constant and saturation current is greatly reliant on light, the ideality factor of such a diode increases to 6.9 which confirms the non-ideality of such device.

Near-infrared fluorescence (NIRF) imaging involves the separation of weak fluorescence signals from backscattered excitation light. The measurement sensitivity of current NIRF imaging systems is limited by the excitation light leakage through rejection filters. In this contribution, the authors demonstrate that the excitation light leakage can be suppressed upon using appropriate filter combination and permutations. The excitation light leakage and measurement sensitivity were assessed and compared in this study by computing the transmission ratios of excitation to emission light collected and the signal-to-noise ratios in well-controlled phantom studies with different filter combinations and permutations. Using appropriate filter combinations and permutations, we observe as much as two orders of magnitude reduction in the transmission ratio and higher signal-to-noise ratio.