Romli Mohamad

Performance of All-Optical Multicasting Via Dual-Stage XGM in SOA for Grid Networking

The letter presents a study on the performance of an all-optical multicasting technique utilizing the nonlinearity of semiconductor optical amplifier (SOA) technology for all-optical grid computing network. The technique not only has the capability to optically control the degree of multicasting but also performs all-optical switching simultaneously. Experimental results show the designs capability to multicast an incoming 10-Gb/s optical signal onto 16 outgoing signals using cross-gain modulation in a single SOA. A second SOA is also included in the design as a 2R regenerator

CWDM PON system: Next generation PON for access network

In this paper, authors proposed and developed CWDM PON system for next generation PON implementation. Its physical link performance and network traffic simulation has been demonstrated experimentally. A laboratory setup has been made with modulated data traffic is pumped into the systems physical link. The N2X Agilent is used to inject data traffic to the system. The results will prove the ability of the developed CWDM-PON system to deliver high speed broadband services to the subscribers.

Live HD video transmission using 40GHz radio over fibre downlink system

40GHz radio over fibre (ROF) downlink system is constructed to demonstrate HD video transmission capability using the hybrid optical and wireless system. The dual-sideband optical carrier suppression (DSB-OCS) technique is used in conjunction with the minimum transmission bias (MiTB) to generate optical millimetre wave signal by utilizing a dual electrode Mach-Zehnder modulator (DE-MZM). A baseband high definition (HD) video signal is modulated into the system via a second MZM. The signal is distributed to a remote antenna unit (RAU) using a 20km optical fibre, then transmitted wirelessly to a customer premise equipment (CPE) located at 5m away. The results show that the HD video is successfully transmitted over the error free 40GHz ROF downlink system.

Internally generated 21.6-GHz millimeter wave based on brillouin fiber laser

An all-optically generated millimeter wave carrier at 21.67 GHz is experimentally achieved. This frequency is realized when two consecutively generated laser wavelength are heterodyned on the 60 GHz high-speed photodiode. The mixing between the Brillouin pump and the second-order Stokes wavelengths is spaced by 1.7 nm. This spacing, which is doubled from inherently generated Stokes shift, is accomplished through the isolated circulation of the first order Stokes wave in the double Brillouin Stokes shifter built with 25-km single mode fiber. The generated millimeter carrier is measured at 21.68 GHz, and its carrier phase noise and threshold power are −58.67 dBc/Hz and 19 mw of Brillouin pump power respectively.

Effect of Laser Bias Current to the Third Order Intermodulation in the Radio over Fibre System

Third order intermodulation (IM3) can cause non-linearity effects which result in interference and crosstalk between the subcarriers in radio over fibre (ROF) transmissions. This paper presents the experimental results of the effect of varying the magnitude of the laser bias current on the IM3 in an ROF system with direct modulation. We also investigate the behaviour of the system spurious free dynamic range (SFDR) with the bias current variation. The results show that there will be an optimum bias current range for a given range of the radio frequency (RF) input power in order to minimise the IM3 effect and obtain the best possible SFDR for the system

Adopting Electroabsorption Modulator for the WLAN 802.11a Radio over Fibre System

This paper presents the evaluation of radio over fibre (ROF) capability with electroabsorption modulator (EAM) as a downlink photodetector (PD) and uplink radio frequency (RF) modulator. The results show that the EAM device has potential to be adopted as the transceiver at the remote antenna unit (RAU) for the system. The 130 m ROF system with biased EAM is capable to obtain a symmetrical WLAN 802.11a data rate of 18 Mbps with laser diode output power of 8.7 dBm.

Characterisation of DSB-OCS technique for 40GHz radio over fibre system

The dual sideband optical carrier suppression (DSB-OCS) technique is characterised for its performance in order to be used as a carrier for 1.25Gbps OOK signal in the 40GHz radio over fibre (ROF) system. A dual electrode Mach-Zehnder modulator (DE-MZM) and the minimum transmission bias (MiTB) technique are employed to build the system. The results show that, a 40GHz carrier is successfully generated with the amplitude up to -29dBm and SNR of 35dB. Finally, an error free 40GHz ROF system is constructed with almost no penalty between the back to back and 20km fibre for a BER of 10-9.

The challenge for active and passive components design in CWDM PON system co-exist in GEPON and 10 GEPON architecture

In this paper, we proposed a CWDM PON system as a Next Generation PON system coexists with 1.25/2.5GEPON and 10GEPON system. In CWDM PON system the most challenging part is to provide passive and active components in the network. This study focused on the effect of the active and passive component in the developed CWDM PON system.

Performance and dispersion analysis for 40GHz multi wavelength optical carriers for radio over fiber system

This paper presents optical system analysis on 40GHz multi wavelength optical carriers for radio over fiber using double side band optical suppressed carrier. Since this simulation model deployed data rate transmission at 40Gbps, therefore the dispersion factor has to be included in the system analysis. The post-dispersion compensation scheme is used in this model to compensate the dispersion along the 30 km transmission fiber length.

Spectral variation in Brillouin-Raman fiber laser

This article discusses the optical-SNR variation of Stokes lines in Brillouin-Raman fiber laser. This variation is partly attributed to the cavity modes interaction through intraline-FWM residing the same spectral width. The worst OSNR is obtained at 650 mW Raman pump power (RPP) and 1555 nm Brillouin pump wavelength (BPW). The improvement is obtained for the RPP beyond 650 mW.