S-band gain flattened distributed fiber Raman amplifier with chirped fiber bragg grating filter

IPTV,video-phone,video-conference,distance learn-ing,distance medical ,e-governmental affairs ,etc .will be-come commonthings in people' s daily life with the fastdevelopment of Internet technology.During this processextra-capacity of fiber communication …     

Box-like spectral response of a series-coupled microring resonant filter in a parallel channel

Inthelast decades ,microring resonator( MRR) wave-lengthfilters are developed rapidly because of their po-tential applications in wavelength division multiplexing( WDM) communicationsystems andtheir excellent fea-tures includingfunctionality,compactness a…     

Statistical characteristics and effects of polarization mode dispersion in dispersion managed soliton systems

Recently,the dispersion-managed solitons(DMS) areof great interest in soliton communication systems .Be-cause of some prior advantages compared with conven-tional solitons ,such as higher pulse energy and signalnoise ratio,lower averaged dispersionline an…     

Novel algorithm of finding good candidate pre-configuration cycles in survivable WDM mesh network

Pre-configuration Cycle (p-cycle) is a promising ap-proach for protecting working capacities in WDMnet-works because of its ability to achieve ring-like recoveryspeed while maintaining the capacity efficiency of amesh-restorable network[1].The first and t…     

Simulation of chaotic synchronization communication system based on incoherent optical feedback and injection

Chaotic communicationis of great interest because ofa potential applications in secure communications andspread spectrumcommunications .Asemiconductor lasersubject to optical feedback is known to have complexdynamic behavior ,and it can produce chaotic wa…     

Supercontinuum generation pumped by a regeneratively mode-locked fiber laser

Supercontinuum（SC） generation in a dispersion-shifted fiber（DSF） pumped by a 10 GHz regeneratively mode-locked fiber laser（RMLFL） is presented. Optimization of pump wavelength leads to a 20 dB bandwidth of 58.73 nm,which covers the whole C band and part of L band. Using an angle-tuning thin film filter, multi-wavelength and pico-second pulse trains of low chirp could be chosen from the SC spectrum. Amplified spontaneous emission（ASE） induced degeneration of the achieved pulse trains is observed and discussed.     

Improvement of normalized throughput in WDM ＋ OCDMA system using optical hard-limiters

Recently,because of advantages of high-speed opticalprocessing and si mple network control ,the optical codedivision multiple access (OCDMA) has become a hotscheme in LAN and access network[1-5]. According tothe spreading mode, OCDMAcan be mainly dividedi…     

Design of buffer structure at core nodes in optical burst switching

DrivenbybothpromptincreaseofIPserviceandvast bandwidthofWDM,conventionalopticalnetworksareevolvingintothenextgenerationopticalInternet(NGOI).Somefunctionsofconfiguration,performance andfaultmanagement,executedinelectronicdomainatpresent,willbeshiftedintoo…     

New scheme of optical switch technology of time division

Intheopticalnetwork,opticalswitchcanrealizethe signaltransformandswitchinopticalfield.Thetechnol ogyincludeswavelengthdivisionandtimedivision.Thetimedivisionswitchisthebestsolution,whileitisdiffi culttoberealized,especiallyforthelargescaleandlittle timesl…     

Narrow-channel-spacing 32-channel AWG multiplexer with an innovative alignment method

A 32-channel 50 GHz spaced arrayed-waveguide grating（AWG） with our innovative configuration has been designed and fabricated. The performance of the device has been fully tested by using a system that consists of a tunable laser light source （TLS）, an optical power meter and a polarization controller. The insertion loss （IS） of the device is 4.2-7.4 dB. The crosstalk is about - 28 dB. The IS uniformity is less than 3.3 dB. With our configuration,the performance of the device has been enhanced effectively and the difficulty in alignment process has been decreased obviously.     

Pulse-width compression based on photonic crystal fiber

Since the first PCF was fabricated in 1996 ,PCF hasattractedthe significant attention due toits unique char-acteristics . One of the highlights is that ,according tothe flexibility of conveniently changing the core area ofPCF,a smaller mode-field area can…     

Research on highly nonlinear photonic bandgap fibers

Since thefirst photonic crystal fiber (PCF) wasfabri-cated by Knight J C and his colleagues[1]at 1996 ,thistype of fibers ,consisting of a central defect region sur-rounded by multiple air holes running alongits length,has been the subject of much interes…     

Generation of low jitter and discrete tunable dual-wavelength optical pulses at arbitrary repetition rates

Recently there is an increasing interest in generatingshort optical pulses with lowti ming jitter and tuneablemulti-wavelength due toitsi mportant applicationin op-tical ti me division multiplexed(OTDM),wavelength di-vision multiplexed(WDM)systems,and opt…     

Laser-diode pumped Nd: GdVO4 ultraviolet laser with LBO frequency tripling

We have demonstrated a laser-diode pumped Nd.GdVO4 extra-cavity frequency tripling ultraviolet laser with a LBO crystal in this paper. Under the acousto-optic （A-O） Q-switched operation, we have obtained 355 nm ultraviolet laser,with pulse width of 25 ns and pulse repetition rate of 20 kHz. By using a type Ⅰ non-critical phase-matched LBO crystal, the SHG output power of 822 mW is achieved at the incident pump power of 16 W. The output power of 355nm UV laser is 260mW with a type Ⅱ phase-matched LBO crystal,and the conversion efficiency （1 064 nm-355 nm） is 5.9 %. The power stability of 355 nm laser is 1.7% in 1 h.     

Quality improvement of the dual-wavelength signals in DLOB via power equalization

The data packet buffeting can be implemented in dual loop optical buffer （DLOB） through cross-phase modulation （XPM） between the control signal and the data packets. However, the output equality of dual wavelength signals will degrade due to the unbalanced gain and phase shift. This problem can be resolved by power oqualizafion using the saturation characteristics of SOA. The data packets with 2.5 Gb/s can be buffered in DLOB for 16 cycles corresponding to 16.5 μs.The extinction ratio of the output packet is 8 dB while the S/N is 8.1 dB.     

Research on fault location technology based on BP neural network in DWDM optical network

BP neural network is introduced to the fault location field of DWDM optical network in this paper. The alarm characteristics of the optical network equipments are discussed, and alarm vector and fault vector diagrams are generated by analyzing some typical instances. A 17 × 14 × 18 BP neural network structure is constructed and trained by using MATLAB. By comparing the training performances, the best training algorithm of fault location among the three training algorithms is chosen. Numerical simulation results indicate that the sum squared error （SSE） of fault location is less than 0.01, and the processing time is less than 100 ms. This method not only well deals with the missing alarms or false alarms, but also improves the fault location accuracy and real-time ability.     

Supercontinuum generation in a Bragg fiber：a novel proposal

Nonlinear optical effects such as self-phase modula-tion,four-wave mixing,cross-phase modulation,sti mula-ted Raman scattering,together with appropriate tempo-ral dispersion profileinan optical fiber couldsignificant-ly broaden ( >100 nm) the spectrumof a…     

Design of low-confinement-loss and highly birefringent index-guiding photonic crystal fibers

We present a systematic scheme to achieve both high birefringence and low confinement loss in index-guiding photonic crystal fibers （PCFs）, using a structurally-simple PCF with finite number of air holes in the cladding region. By increasing the size of the outermost-ring air holes in the cladding region, highly birefringent PCFs with low confinement loss can be successfully achieved. The design strategy is based on the fact that the modal birefringence of PCFs is dominated by the inner-ring air holes in PCF, which is verified by a full-vector finite element method with anisotropic perfectly matched layers. Numerical results show that modal birefringence in the order of 10-3 and confinement loss less than 0.1 dB/km can be easily realized in the proposed PCF with only four rings of air holes in the cladding region. We expect that such fibers will be much easier to be fabvicated than those with more air holes in the cladding region.     

Optical interconnection on PCB level using MT compatible connectors and fiber-embedded boards

Thanks to the fast development of VLSI technology,great changes havetaken place bothinscientific area andour daily lives : Complex scientific experi ments can bedonein computer without great cost or side effects ;ournetworking systems work faster ;pocket …