in this paper, the effects of reflected waves of the facets on the internal optical intensity of semiconductor dfb lasers are investigated. the uniformity of optical intensity along the cavity length is evaluated with flatness parameter. the dependence of this parameter on coupling coefficient, reflectivity and grating phase at the facets is also studied. this investigation shows that in some s...

This study reports an application of instrumental color measurement for quantifying and comparing the optical properties of high density polyethylene HDPE and low density polyethylene LDPE blend films and the effect of blending ratio and miscibility on these properties. The technique of spectrophotometry in transmission and reflectance modes can be used as a versatile tool to evaluate the color...

In this article, ZnO and ZnO:Mn nanoparticles prepared by reverse micelle method. The various crystalline properties of these nanoparticles such as size, d-spacing, strain, stress, dislocation density and texture coefficient have been calculated with the help of XRD spectrum. The XRD results indicated that the synthesized ZnO and ZnO:Mn nanoparticles have a pure wurtzite (hexagonal phase) struc...

In this article, ZnO and ZnO:Mn nanoparticles prepared by reverse micelle method. The various crystalline properties of these nanoparticles such as size, d-spacing, strain, stress, dislocation density and texture coefficient have been calculated with the help of XRD spectrum. The XRD results indicated that the synthesized ZnO and ZnO:Mn nanoparticles have a pure wurtzite (hexagonal phase) struc...

In this paper, a numerical study of barrier characterization effects on the high-temperature internal performance of an InGaAsP multi-quantum well laser is presented. The softwareused for this purpose self-consistently combines the three-dimensional simulation of carrier transports, self-heating, and optical waveguiding. The laser model calculates all relevant physical mechanisms, including the...

The distribution of cone photopigment across the retina affects the amount of light captured by cones at each retinal location. Cone photopigment optical density is measured in two ways, with reflectometry and/or with color matching. Color matching measures a higher optical density than does reflectometry. Control experiments confirm that large-field color matches measure photopigment optical d...

Since the introduction of optical data storage systems in the 1970s, we have observed a stepwise increase in their storage capacity using the same means for resolution improvement as in classical microscopy and optical lithography, namely, a reduction in the source wavelength and an increase in the numerical aperture of the imaging optics. In this paper we briefly address the historical develop...