368 research outputs found
Reconfigurable multi-level phase shift keying encoder-decoder for all-optical networks
No full textWe demonstrate the application of a uniform Bragg grating as a dynamically reconfigurable phase encoder-decoder for optical systems. Precise discrete phase modulation between chips is obtained simply by heating segments along the grating with fine resistive wires. Its reliability to generate and recognize various phase code sequences is demonstrated in a 16-chip 20-Gchip/s quaternary phase-shift keying coherent optical code-division multiple access experiment. The bit-error-rate response is also included to highlight its performance
Rapidly reconfigurable optical phase encoder-decoders based on fiber Bragg gratings
No full textWe demonstrate the capacity for fast dynamic reconfiguration of optical code-division multiple access (OCDMA) phase en/decoders based on fiber Bragg gratings and a thermal phase-tuning technique. The tuning time between two different phase codes is measured to be less than 2 s. An OCDMA system using tunable-phase decoders is compared with a system using fixed-phase decoders and, although the system using fixed-phase decoders exhibits a shorter output autocorrelation pulsewidth and lower sidelobes, the system using tunable-phase decoders has advantages of flexibility and a more relaxed requirement on the input pulsewidth
Industrial training report: Perpustakaan Tun Abdul Razak (PTAR) UiTM Cawangan Perak, Seri Iskandar / Ruhi Imani Mokhtar
No full textThis report is contained information about the industrial training of Ruhi Imani Binti Mokhtar in Perpustakaan Tun Abdul Razak (PTAR) library, UiTM Perak Campus Seri Iskandar starts from 01 August until 31 December 2017. A detailed information about the organization background and PTAR library UiTM Perak is stated by the author. All the activities that happened during the industrial training is also been explained according to the department of the library. A special project for this industrial industry is also been explained by the author in detail. This report also did explain about the reflection that has been got by the author during of his internship. Appendices that related to the industrial training is also included
Tuneable second harmonic generation in long periodically poled optical fibres
No full textA widely tuneable second harmonic generator in a periodically poled germanosilicate optical fibre is demonstrated for the first time. Broadband wavelength tuning of 27.8nm is achieved using a highly efficient compression tuneable package demonstrated with fibre Bragg gratings
Photosensitivity in germanium-free antimony doped alumino-silicate optical fibre prepared by MCVD
No full textBragg gratings with index modulations of ~3 x 104 is reported in antimony (Sb) codoped fibres. Gratings in germanium-free fibres of different Sb concentration are analysed and those in higher concentration fibres are found the more temperature-resistant
A novel distributed ODCMA architecture based on simultaneous transmission of 16-chip OCDMA signals and clock pulses
No full textWe demonstrate a distributed bi-directional OCDMA architecture suitable for secured access networks, incorporating a fast 16-chip code-tunable encoder based on a uniform fibre Bragg grating and fixed-code superstructure fibre Bragg grating. This simple architecture eliminates the requirement for expensive laser transmitters at the subscribers' terminal
Simple dynamically reconfigurable OCDMA encoder/decoder based on a uniform fiber Bragg grating
No full textA simple reconfigurable phase coding OCDMA coder/decoder based on a uniform fiber Bragg grating is proposed and demonstrated. Experiments using the temperature-tunable 8-chip, 20 Gchip/s bipolar coding/decoding gratings show its excellent code recognition features
16-bit multilevel reconfigurable phase encoder for all optical header generation/recognition based on a uniform fibre Bragg grating
No full textWe demonstrate a simple, dynamically tunable phase encoder/decoder for use in reconfigurable all-optical packet switched networks. The device is based on a uniform fibre Bragg grating and has 16 phase-tunable elements. Excellent auto-/cross-correlation features and error free BER operation are obtained
Investigation into the photosensitivity of germanium-free antimony co-doped alumino-silicate optical fibres
No full textPhotosensitivity of different concentrations of antimony (Sb) codoped alumino-silicate optical fibres are analysed. Bragg gratings with index modulations of ~3 x 10-4 are reported. The temperature stability of the gratings is tested and those in higher concentration fibres are found to be more temperature-resistant
Direct characterization of the spatial effective refractive index profile in Bragg gratings
No full textWe propose a pulse response method to directly characterize the phase of the spatial index modulation, including the dc refractive index distribution (distributed phase shift), discrete phase, and chirp of fiber Bragg gratings (FBGs). This method is based on the observation that the spatial phase of gratings is directly related to the temporal phase of its pulse response. Therefore, the phase of the spatial index modulation can be characterized directly by measuring the temporal phase of the pulse response of FBGs. This method is then used to characterize an FBG with a current-induced phase shift
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