Design and Investigations with all Optical Multilogic Network

This article presents investigation for all optical multilogic function in the proposed single photonic network. Logic operations the AND, OR, NOR, XNOR, NOT, Buffer, $\bar AB$, $A\bar B$ have been executed simultaneously at higher data rate for nonreturn-to-zero pattern on the different C-band wavelengths. Numerous logic functions have been accomplished by the optical multiplexer, couplers exploiting SOA nonlinearities, which are else contemplated as cons, if SOA is exercised as an amplifying device. Numerical simulation for parameters as bias voltage of the modulator, nonreturn-to-zero, return-to-zero, Mach-Zehnder type modulation formats, data rate and numerous drives as on-off-ramp, raised cosine, on-off-exp, on-off in conjunction with key design features length, width, thickness of SOA have been aptly explored in terms of the extinction factor. Investigations depicted good performance for the nonreturn-to-zero format. Accordingly, output patterns for the multilogic executions have been verified at 10 Gbps data rate with nonreturn-to-zero pattern. The proposed schematic could be one of the feasible means for the design of upcoming composite photonic computation higher data rate links, as it excludes need for most expensive optoelectronic translations.

Relation between weather radar equation and first-order backscattering theory

Aim of this work is to provide a new insight into the physical basis of the meteorological-radar theory in attenuating media. Starting form the general integral form of the weather radar equation, a modified form of the classical weather radar equation at attenuating wavelength is derived. This modified radar equation includes a new parameter, called the range-bin extinction factor, taking into account the rainfall path attenuation within each range bin. It is shown that, only in the case of low-to-moderate attenuating media, the classical radar equation at attenuating wavelength can be used. These theoretical results are corroborated by using the radiative transfer theory where multiple scattering phenomena can be quantified. From a new definition of the radar reflectivity, in terms of backscattered specific intensity, a generalised radar equation is deduced. Within the assumption of first-order backscattering, the generalised radar equation is reduced to the modified radar equation, previously obtained. This analysis supports the conclusion that the description of radar observations at attenuating wavelength should include, in principle, first-order scattering effects. Numerical simulations are performed by using statistical relationships among the radar reflectivity, rain rate and specific attenuation, derived from literature. Results confirm that the effect of the range-bin extinction factor, depending on the considered frequency and range resolution, can be significant at X band for intense rain, while at Ka band and above it can become appreciable even for moderate rain. A discussion on the impact of these theoretical and numerical results is finally included.

Relation between weather radar equation and first-order backscattering theory

Aim of this work is to provide a new insight into the physical basis of the meteorological-radar theory in attenuating media. Starting form the general integral form of the weather radar equation, a modified form of the classical weather radar equation at attenuating wavelength is derived. This modified radar equation includes a new parameter, called the range-bin extinction factor, taking into account the rainfall path attenuation within each range bin. It is shown that, only in the case of low-to-moderate attenuating media, the classical radar equation at attenuating wavelength can be used. These theoretical results are corroborated by using the radiative transfer theory where multiple scattering phenomena can be quantified. From a new definition of the radar reflectivity, in terms of backscattered specific intensity, a generalised radar equation is deduced. Within the assumption of first-order backscattering, the generalised radar equation is reduced to the modified radar equation, previously obtained. This analysis supports the conclusion that the description of radar observations at attenuating wavelength should include, in principle, first-order scattering effects. Numerical simulations are performed by using statistical relationships among the radar reflectivity, rain rate and specific attenuation, derived from literature. Results confirm that the effect of the range-bin extinction factor, depending on the considered frequency and range resolution, can be significant at X band for intense rain, while at Ka band and above it can become appreciable even for moderate rain. A discussion on the impact of these theoretical and numerical results is finally included.

Response to Larsen & Thorkildsen's comments onExtinction-corrected mean thickness and integrated width used in the program UMWEG98

Some additional comments are made concerning the asymptotic expressions for the primary-extinction factor for a perfect spherical crystal.