Comparison between Direct and Coherent Optical Communication System

The work in this paper focuses on the system quality of direct and coherent communication system for two computers. A system quality is represented by Signal to Noise ratio (SNR) and Bit Error Rate (BER). First part of the work includes implementation of direct optical fiber communication system and measure the system quality .The second part of the work include implementation both the( homodyne and heterodyne)coherent optical fiber communication system and measure the system quality . Laser diode 1310 nm wavelength with its drive circuit used in the transmitter circuit . A single mode of 62.11 km optical fiber is selected as transmission medium . A PIN photo detector is used in the receiver circuit. The optical D-coupler was used to combine the optical signal that come from transmitter laser source with optical signal of laser local oscillator at 1310/1550 nm to obtain coherent detection . Results show that for direct detection the SNR and the BER (28.5 dB, 9.64x10-8,) respectively, while for homodyne and heterodyne coherent detection , the SNR(94.36,97.71)dB and the BER are (1.32x10-22,2.43x10-23) at maximum optical fiber length at 62.11 km. Results show that the homodyne and heterodyne detection are better than direct detection because the large output SNR and low BER of the received signal

TiO2- CuI Nanoparticle /Ru Solid State Dye-Sensitize Solar Cells

In this work  solid state dye sensitized solar cell (SSDSSC) type  (ITO / TiO2/ Ru / CuI / Ag) is fabricated. The thin films are prepared by pulse laser deposition (PLD) technique under the vacuum pressure of 3×10−3 mbar and annelid at 450 oC. In this technique  Nd:YAG laser at 1064 nm wavelength with (200 , 500 , 800) pulsed was used. It was noticed from (I-V) characteristics of the solar cell that  the photocurrent  collected  from  the  TiO2  (NP)  is increase as the number of  laser pulses increase. The conversion efficiency of TiO2 is increased  from 2.115%  up  to  5.654% and for CuI from 1.73 % to 5.19 % when the number of pulses increase from 200 up to 800

TiO2- CuI Nanoparticle /Ru Solid State Dye-Sensitize Solar Cells

In this work  solid state dye sensitized solar cell (SSDSSC) type  (ITO / TiO2/ Ru / CuI / Ag) is fabricated. The thin films are prepared by pulse laser deposition (PLD) technique under the vacuum pressure of 3×10−3 mbar and annelid at 450 oC. In this technique  Nd:YAG laser at 1064 nm wavelength with (200 , 500 , 800) pulsed was used. It was noticed from (I-V) characteristics of the solar cell that  the photocurrent  collected  from  the  TiO2  (NP)  is increase as the number of  laser pulses increase. The conversion efficiency of TiO2 is increased  from 2.115%  up  to  5.654% and for CuI from 1.73 % to 5.19 % when the number of pulses increase from 200 up to 800