Showing 4 results for Ber.
Supriya Patil, A.d. Shaligram,
Volume 5, Issue 2 (7-2011)
Abstract
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 the diesel then diesel acts as a cladding for uncladded S shape portion of optical fiber. As diesel is adulterated by different volumes of kerosene, refractive index of cladding changes which in turn affects the output intensity of the sensor. The investigation revealed that when such structure of sensor is used to detect the adulteration level in diesel then sensitivity gets improved 4 times for two fold increase in bend curvature of fiber. Thus it is highly sensitive mechanism to determine on line adulteration of diesel and also can be used for other applications.
Keshavarz, Kazempour,
Volume 6, Issue 2 (10-2012)
Abstract
The ABCD matrix method is used to simplifying the theoretical coupling efficiency calculation of Elegant Hermite-Cosh-Gaussian (EHChG) laser beams to a Single Mode Fiber (SMF) with a quadric lens formed on the tip. The integrals of coupling efficiency relation are calculated numerically by Boole method. Meanwhile, the structure parameters of surface-lensed fiber are optimized in numerical simulation to achieve maximum coupling efficiency. Results can give some guidance suggestions for designing suitable micro lenses in order to coupling the EHChG laser beams to the SMF.
Abbas Hamooleh Alipour, Ali Mir,
Volume 13, Issue 2 (12-2019)
Abstract
In this paper, an enhancement design of communication system using optical radio frequency (RF) waves in free space optical communication (FSO) system is presented. To our knowledge, it is the first time that the effect of Gamma-Gamma turbulent channel model on the performance of the proposed system is analyzed and simulated. To obtain an optical communication system with good performance and high spectrum efficiency, we proposed two types of optical RF waves including optical single sideband (OSSB) and optical double sideband (ODSB). This strategy that integrated an optical communication system with turbulent channel model can express an accurate model of optical and RF waves propagation in free space. Performance of the system under different regimes, weak, moderate and strong turbulent is studied considering several parameters like max quality factor, bit error rates (BER), and optical signal-to-noise ratio (OSNR). Also, a comparative study between two methods of optical RF waves is presented.
Erfan Abbaszadeh Jabal Kandi, Khosro Mabhouti, Rahim Naderali, Neda Samadzadeh,
Volume 17, Issue 1 (1-2023)
Abstract
In this article, the conditions of pulse production in two mutually coupled lasers are studied. Based on the obtained characteristic equation and its roots, the dynamical behavior of the system and the threshold of the instability are analyzed. For the stable operation of the system and with the use of the time series curves, it is possible to study the dynamical behavior and the stability ranges of the laser in the presence of the saturable absorber and the gain environment. This paper aims to achieve from quasi-periodic behavior in a solitary laser to the generation of a pulse train from two mutually coupled lasers in the presence of saturable absorbers. Also, the stability range for a solitary laser and then for two coupled lasers in the presence of saturable absorbers have been studied.
