Growing demands of the internet users is one of the reasons that lead using dense wavelength division multiplexing (WDM) networks to transmit optical data. This modulation technique has the capability of transmitting several wavelengths... more
Growing demands of the internet users is one of the reasons that lead using dense wavelength division multiplexing (WDM) networks to transmit optical data. This modulation technique has the capability of transmitting several wavelengths through a single optical fiber. In this study, we have simulated a 160 Gb/s DWDM network with transmission power of 0 dBm, using NRZ encoding technique through a 32-chanels optical transmitter over a distance of 1000 km. To this aim, we have assumed a link of 10 spans with a length of 100 km fiber for each span. An EDFA and a DCF have been used for amplifying signals and compensating pulse dispersion, respectively. All simulations have been run by using Optisystem software. The quality of the network was estimated by using the eye-diagrams of the received signals. The maximum quality factor of 20.7 and minimum bit error rate of 7.6×10-95 are obtained at wavelength of 1552.5 nm. The eye-diagrams showed an ideal quality for the received signals. More research works are needed to evaluate the parameters that affect on the quality of the DWDM optical systems.
This article shows the development of a photonic detector of low-frequency ultrasonic signals. These signals latter reach a sensitive single-mode optical fiber as an acoustic guide conveying the signals (around 43 kHz) over 70 cm to a... more
This article shows the development of a photonic detector of low-frequency ultrasonic signals. These signals latter reach a sensitive single-mode optical fiber as an acoustic guide conveying the signals (around 43 kHz) over 70 cm to a distant and protected in-fiber Bragg grating. The grating reflects a spectrum centered around 1550 and 2.6 nm band-width and is interrogated by a tunable laser in their linear and most sensitive region. As a result, real-time passive demodulation of communication or monitoring of ultra-sonic signals propagating through solid materials is possible. The detector may also be applied to other physical media. In this study, a new passive technique to thermally desensitize the fiber-Bragg gratings (FBG) is also proposed, though the proposed technique is not experimentally tested.
