In this paper, the Staged Reservation Scheme (SRS) is introduced for Optical Burst-Switched (OBS) networks based on Just-Enough-Time (JET) protocol. With SRS the Data-Bursts are segmented into equal sub-bursts (data segments). SRS is to address the feasibility issues (e.g. segments delineation, and trailer-messages creation) associated with the implementation of burst segmentation techniques. The burst control packet is modified to carry the segments' number and length, therefore the data-bursts length. Furthermore, the network resource reservation is performed in stages to resolve contentions at the control packets level, and to reduce the packets loss probability.
A novel balance detection scheme for high-speed optical frequency-shift-keying (FSK) transmission was proposed. Fiber dispersion can be compensated by a balanced photodetector with an optical delay. 10Gbit/s optical FSK transmission over a 130km single mode fiber was demonstrated, where the FSK signal was generated by using aLiNbO3 high-speed optical FSK modulator.
We propose a novel optical-regenerator based on two-transverse mode VCSEL with dual optical-injection locking. The nonlinear transfer function in input-output characteristics enables us to reshape the degraded input signal. In addition, the polarization state of the output signal can be tightly controlled. The CW assist light injected into the fundamental transverse mode increases the speed and stabilizes the polarization of the output light at the same time. A possibility of 4R (3R+Re-polarization) regeneration at 10 Gbps is suggested.
A directly modulated AM-VSB CATV EDFA-repeated system that uses split-band technique and optical single sideband (SSB) filter at the receiving site is proposed and demonstrated. Good performances of CNR, CSO and CTB were achieved for the full channel band over a-120km single-mode fiber (SMF) transport. Our proposed system is suitable for the fiber optical CATV systems in long-haul transport.
A novel authentication approach which based on the integration of tokenised pseudo-random numbers and the user's iris biometrics, to generate a user-specific binary bitstring via an iterated inner-product mechanism is proposed. The proposed method, S-Iris encoding, protects against iris fabrication as it can only contribute to the authentication process when both the genuine biometrics template and pseudo-random number are presented. It also enables straightforward revocation via token replacement. Furthermore, S-Iris Encoding reduces length of iris feature to around 5% of its original size yet able to attain an approximately 0% of Equal Error Rate (EER).This approach also shows the effectiveness and accuracy in term of verification rate if compared to the traditional biometrics system or the straightforward use of two authentication schemes in parallel.
A low-threshold-current distributed reflector laser consisting of phase-shifted distributed feedback (DFB) grating and quantum-wire distributed Bragg reflector (DBR) sections was realized. The device with a DFB length of 150µm, a DBR length of 240µm and a stripe width of 1.5µm achieved a threshold current as low as 1.2mA and a differential quantum efficiency of 13% from the front facet under RT-CW conditions. A good single-mode operation was also realized at a mode determined by the phase-shifted grating.