[Show abstract][Hide abstract] ABSTRACT: We experimentally demonstrate the use of saw-tooth optical pulses, which are shaped using a fiber Bragg grating, to achieve robust and high performance time-domain add-drop multiplexing in a scheme based on cross-phase (XPM) modulation in an optical fiber, with subsequent offset filtering. As compared to the use of more conventional pulse shapes, such as Gaussian pulses of a similar pulse width, the purpose-shaped saw-tooth pulses allow higher extinction ratios for the add and drop windows and significant improvements in the receiver sensitivity for the dropped and added channels.
[Show abstract][Hide abstract] ABSTRACT: Fibre grating technology can be used to design and fabricate reflective filters with accurately controlled complex phase and amplitude responses and thereby provide a powerful means to reshape short optical pulses in both time and frequency. We review recent progress in the area and present various applications focussed primarily in the areas of all-optical coding and decoding, and pulse retiming.
[Show abstract][Hide abstract] ABSTRACT: A time-division add-drop multiplexer capable of high-extinction-ratio operation is presented both theoretically and experimentally. The approach used is based on time-to-frequency domain conversion of optical signals and relies upon the switching of linearly chirped optical pulses. By converting a 40-Gb/s optical time-division multiplexing (OTDM) signal to 4 × 10-Gb/s wavelength-division multiplexing (WDM) channels and using fiber Bragg gratings for frequency-domain add-drop multiplexing, a timeslot suppression ratio in excess of 30 dB and error-free operation for the dropped, through, and added channels were achieved. A further stage of WDM-to-TDM signal conversion was used to map the resulting signal back into the time domain. Moreover, it is shown that it is straightforward to simultaneously operate on multiple channels by simply cascading gratings to make more complex filtering functions without the requirement for any further synchronization of the tributary channels.
Full-text · Article · Aug 2006 · Journal of Lightwave Technology
[Show abstract][Hide abstract] ABSTRACT: Quadratic optical nonlinearities offer several attractive features for the implementation of ultra-fast, low-noise and transparent telecom devices. Technological progress has dramatically increased their efficiency, driving a steady move towards practical applications. In this talk we shall discuss the use of cascaded quadratic interactions in LiNbO<sub>3</sub> integrated devices for pulse diagnostics, format conversion and signal regeneration in ultra-fast multi-wavelength telecom systems
[Show abstract][Hide abstract] ABSTRACT: We demonstrate a time division add/drop multiplexer based on TDM-WDM-TDM conversion and fiber Bragg grating (FBG) filters with 35-dB channel suppression for the dropped channel. No crosstalk penalty is observed between the added and through channels at 40-Gb/s.
[Show abstract][Hide abstract] ABSTRACT: We demonstrate the complete characterization of short pulses around 1.55 μm by cross-correlation frequency-resolved optical gating based on sum-frequency generation in an integrated LiNbO<sub>3</sub> device. Excellent retrieval is achieved for pulsewidths ranging from 30 to 4 ps.
No preview · Article · May 2005 · IEEE Photonics Technology Letters
[Show abstract][Hide abstract] ABSTRACT: We demonstrate the measurement of short pulses in the 1.55 μm telecommunications window by spectrally resolved cross correlation in an integrated LiNbO<sub>3</sub> device. Extremely high quality pulse retrieval is obtained for pulsewidths down to 4 ps.
[Show abstract][Hide abstract] ABSTRACT: We propose a new approach to generating spectrally flat supercontinuum pulses based on seeding a commercial nonlinear fibre with pump pulses shaped using a superstructured fiber Bragg grating. Experimental results confirm the viability of the approach.
[Show abstract][Hide abstract] ABSTRACT: We demonstrate the simultaneous removal of amplitude and timing jitter from an RZ data-stream using a superstructured fiber grating pulse shape converter and subsequent gating of a clean optical clock in a NOLM.
[Show abstract][Hide abstract] ABSTRACT: We experimentally demonstrate a novel optical packet compression scheme based on linearly chirping the packets followed by dispersive compression and multiwavelength conversion back onto a single wavelength. In particular, four-bit packets at 10 Gb/s were compressed into four-bit packets at 40 Gb/s. Error-free performance was achieved for the final compressed packet.
[Show abstract][Hide abstract] ABSTRACT: We de monstrate a novel and highly flexible approach to OTDM add-drop multiplexing based on OTDM-WDM conversion with an intermediary passive spectral filtering stage. Error-free operation at 40 Gbit/s is
[Show abstract][Hide abstract] ABSTRACT: In this paper, a novel orthogonal wavelength division multiplexing (OWDM) modulation using super-structured fibre Bragg gratings as square pulse shaper followed by orthogonally interleaving the corresponding sinc-function shaped spectrum of each channel is proposed and demonstrated at 10 Gbit/s. The results show that a significant reduction of the interchannel linear crosstalk penalty compared to conventional Gaussian RZ modulation.
[Show abstract][Hide abstract] ABSTRACT: An optical sampling oscilloscope is used to characterize short pulses which have been shaped using superstructured FBGs. The performance of square-pulse-generating and pulse-multiplying gratings are examined directly in real time, with a resolution of 2ps, excellent pulse quality is confirmed.
[Show abstract][Hide abstract] ABSTRACT: Recent advances in optical fibre technology, most notably in the area of microstructured fibres, high power rare-earth doped fibres, and superstructured fibre Bragg gratings offer a host of new opportunities within future high speed communication systems. Herein we review the increased range of waveguide characteristics that can now be obtained within fibre with an emphasis on both fibre nonlinearity and dispersion control, and describe the latest advances in the design and fabrication of fibre Bragg gratings for the manipulation and shaping of ultrashort pulses. We then outline how such components can be integrated into various all-optical processing devices for high speed optical communication systems focusing in particular on data retiming and OTDM add-drop multiplexing.
[Show abstract][Hide abstract] ABSTRACT: We e xperimentally demonstrate a novel optical packet compression scheme based on temporal imaging of TDM packets through time lensing in fibres, while maintaining the pulse width by virtue of soliton propagation during the compression stage. In p articular, 4-bit packets at 10 Gbit/s were compressed into 4-bit packets at 40 Gbit/s. The time lens effect is based on switching the original 10 Gbit/s 4-bit packet with a suitably chirped square pulse and on compressing the chirped packet by propagating it in a standard single mode fibre.