in this paper, an innovative mobile platform is presented which is equipped by three new wheels. the core of the new idea is to establish a new design of rigid circular structure which can be implemented as a wheel by variable radius. the structure of wheel includes a circular pattern of a simple two-link mechanism assembled to obtain a wheel shape. each wheel has two degrees of freedom. the fi...

A novel geometry for enhancing the sensitivity of intensity modulated refractometric fiber optic sensor for detection of adulteration level in diesel by kerosene is proposed. In this multimode plastic optical fiber is uncladded for specific length and bent into S shape. This geometry is simulated and analyzed using Beam Propagation Method in Beam prop RSOFT software. When sensor is immersed in ...

We present a powerful approach towards full understanding of laser light propagation through multimode optical fibres and control of the light at the fibre output. Transmission of light within a multimode fibre introduces randomization of laser beam amplitude, phase and polarization. We discuss the importance of each of these factors and introduce an experimental geometry allowing full analysis...

The results of experiments on Richtmyer–Meshkov instability growth of multimode initial perturbations on an air–sulfur hexafluoride (SF6) interface in a conical geometry are presented. The experiments are done in a relatively larger shock tube. A nominally planar interface is formed by sandwiching a polymeric membrane between wire-mesh frames. A single incident shock wave ruptures the membrane ...

In this paper, we would like to propose a novel design for realizing optical polarization filters and combiners based on multimode interference (MMI) structures using silicon waveguides. The device geometry is simple and eases of fabrication. In addition, analytical and numerical methods are used to optimize the designs for these devices in order to reduce losses and device size.

In this paper, an innovative mobile platform is presented which is equipped by three new wheels. The core of the new idea is to establish a new design of rigid circular structure which can be implemented as a wheel by variable radius. The structure of wheel includes a circular pattern of a simple two-link mechanism assembled to obtain a wheel shape. Each wheel has two degrees of freedom. The fi...

Two-wave mixing (TWM) via a dynamic hologram recorded in a photorefractive crystal allows the implementation of adaptive interferometers. These interferometers can achieve high sensitivity of detection of phase shifts under unstable environmental conditions even when phase shifts are encrypted in speckled waves such as those reflected from rough surfaces or emerging from multimode optical fiber...

We have built a diode-laser-pumped Nd:YAG slab laser that emits 40 W of cw power in a TEM(00) mode and 72 W of power in multimode operation when pumped with 235 W. The slope efficiencies are 22% for TEM(00)-mode operation and 36% for multimode operation. The laser uses a zigzag slab geometry to reduce thermally induced distortions and operates at less than one wave of distortion at the full pum...

This work presents an alternative method for design of refractive index profile for silica GeO2-doped graded-index multimode optical fibers 50/125 with low differential mode delay (DMD), providing equalization between group velocities of selected guided modes. Here the objective function is represented as a sum of squares of deviations between points of current iteration group velocity map, whi...