we solve the coupled mode equations governing the chalcogenide nonlinear fiber bragg gratings (fbgs) numerically, and obtain the bistability characteristics. the characteristics of the chalcogenide nonlinear fbgs such as: switching threshold intensity, bistability interval, on-off switching ratio are studied. the effects of fbg length and its third order nonlinear refractive index on fbg charac...

background: similar to the thermoluminescence (tl) spectra, the optical parameters variations can also be used in tl crystals for dosimetry purposes. these optical parameters can include absorption, transmission and reflection coefficients. materials and methods: single crystals of kbr and kcl which have been used in this research were grown from laboratory grade extra pure precursor powders. c...

In this Article dispersion characteristic of conventional optical waveguide with helical winding at core – cladding interface has been obtained. The model dispersion characteristics of optical waveguide with helical winding at core-cladding interface have been obtained for five different pitch angles. This paper includes dispersion characteristics of optical waveguide with helical winding, and ...

in this article, the effect of cells' radius on the behavior of wavelength switching optical filter andthe effect of the radius of the optical filters' key characteristics such as wavelength resonance onan optical filter based on photonic crystals, have been investigated. currently, the most commonapplied mechanism for designing optical filter based on photonic crystals is using twomechanisms s...

in this article, the effect of cells' radius on the behavior of wavelength switching optical filter andthe effect of the radius of the optical filters' key characteristics such as wavelength resonance onan optical filter based on photonic crystals, have been investigated. currently, the most commonapplied mechanism for designing optical filter based on photonic crystals is using twome...

Background and Aims: Biomolecules' optical and nonlinear optical properties are widely used for different medical diagnoses and applications in biophotonic devices. These properties are essential in studying biological processes in living tissues. Aside from biomolecules' linear optical characteristics, their nonlinear optical characteristics have lately been considered. Materials and Methods:...

the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to ...

The application of surface topography measurement methods to the field of firearm and toolmark analysis is fairly new. The field has been boosted by the development of a number of competing optical methods, which has improved the speed and accuracy of surface topography acquisitions. We describe here some of these measurement methods as well as several analytical methods for assessing similarit...