The interaction of the cavity electromagnetic field with the two-level emitter is described by cavity Quantum electrodynamics (CQED). A pulsed micro-laser is an array of semiconductor Quantum dots (QDs) embedded in an optical micro-cavity. This is one of the basic tools of Quantum information technology. In this study, the energy eigenvalues variations and the Quantum Efficiency of a micro-laser system includes a QD with a decay rate of 0. 8μ eV embedded in the different micro-cavities, were investigated. The results show that with the increasing coherent interaction rate of micro-laser system, the energy eigenvalues variations of this optical system also increase. The Quantum Efficiency for this nano-optical system was studied. The results show the smaller micro-cavity decay rate, the higher Quantum Efficiency at smaller coherent interaction rate. Then, the optimal value of the micro-cavity decay rate was obtained in order to achieve the maximum Quantum Efficiency. The calculation results showed that the highest Quantum Efficiency occurs for optical parameters γ a=0. 8μ eV, g=95μ eV, γ c=177. 7μ eV, and η max=0. 991.

model of a low noise high Quantum Efficiency n+np Germanium Photodiode utilizing ion implantation technique and subsequent drive-in diffusion in the n layer is presented. Numerical analysis is used to study the influence of junction depth and bulk concentration on the electric field profile and Quantum Efficiency. The performance of the device is theoretically treated especially at the wave-length region 1. 55μ m where the Silica optical fiber has minimum attenuation loss. It has been found that at this wave-length and for the optimum device design the Quantum Efficiency approaches about 90%.

Objective(s): Firefly luciferase is a monooxygenase enzyme that emits flash of light during the enzymatic reaction. Luciferase has been used in many bioanalytical fields from ATP detection methods to in vivo imaging. In recent decades, focus has been carried out on nanoparticles for their fluorescence properties. Semiconductor Quantum dots have unique tunable properties that turn them promising tools in biological and biomedical researches, as nanosensors, photo-electrochemical and light-emitting devices. Carbon-based nanoparticles such as graphene Quantum dots (GQDs) have useful benefits such as low toxicity, suitable luminescence and easy preparation. Materials and Methods: In this study, recombinant P. pyralis luciferase was expressed and purified based on N-terminal His-tag and then kinetic parameters of enzyme activity such as Km and Vmax values in presence and absence of GQDs were calculated. Results: The results showed that Km for ATP and luciferin substrates in the presence of GQDs were increased. Fluorescence spectroscopy showed significant changes in protein structure or in fluorescence spectra and decrease in the activity of the luciferase in presence of GQD. Both loss of activity and increase of substrates Km showed decrease of catalytic Efficiency presumably through structural alteration. Conclusion: From these data it can be concluded that the protein structure under the influence of GQD may have changed that lead to alteration of enzyme activity.

In this paper the effects of transmittance, dispersion angle and diffusion length on the Quantum Efficiency of solar cells (QESC) have been simulated and investigated. Optical path technic is used for simulation. The results show that base thickness, diffusion length, dispersion angle, number of optical confinement path and transmission angles have an extremely effects on the QESC. Simulation results show that for 4nsi2 optical paths with j=qL=0 o, 30 o, 60 o and qL=60o QE can be achieved to 72% which is approximately 12% more than qL=0°. The simulation results with grating in SC and reflecting about 100% at the end of the device show that QE increase to %47 with qm=qL=60 o which is more than the results of device without grating. So the results show that the QESC increase with increasing the dispersion angle and diffusion length in the grating device.