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P K A Wai

Publications and source records attributed to P K A Wai.

4 recordsLinked to original sources

Radiating and nonradiating behavior of hyperbolic-secant, raised-cosine, and Gaussian input light pulses in dispersion-managed fiber systems.

We address the problem of optical light pulses, called dressed pulses, which do not match the stationary pulse profile of a dispersion-managed (DM) fiber system and we theoretically analyze the associated radiation. Comparing hyperbolic-secant, raised-cosine, and Gaussian pulse envelopes, we show that the general radiation figure is highly sensitive to the input pulse profile. As common general features for these pulse profiles, we find a rich variety of dynamical states that includes weak-, moderate-, and strong-radiation states, depending on the map strength of the DM fiber system. We demonstrate the existence of two intervals of map strengths where the emitted radiation is of considerably low level. The first interval falls in a region of small map strengths where pulses are weakly dressed. In contrast, the second window of low radiation appears in the map strength region corresponding to strongly dressed pulses. As a major difference with respect to the pulse profile, we find that light pulses with Gaussian input profile produce less radiation in the fiber system than hyperbolic-secant or raised-cosine pulses can do. In particular, at the lower edge of the second window of low radiation, Gaussian light pulses with large initial dressing acquire the best ability to execute a stable nonradiative propagation over transoceanic distances.

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All-optical add-drop node for optical packet-switched networks.

We have demonstrated all-optical packet add-drop for all-optical packet-switched networks. Intelligent all-optical add-drop of packets is performed, based on all-optical processing of packet headers. The header and payload rates are 5 and 10 Gbits/s, respectively.

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Amplification and compression of ultrashort fundamental solitons in an erbium-doped nonlinear amplifying fiber loop mirror.

A nonlinear amplifying loop mirror constructed from erbium-doped fiber is proposed for simultaneous amplification and compression of ultrashort fundamental solitons. Numerical simulations show that, unlike conventional erbium-doped fiber amplifiers in which nonlinear effects lead to serious degradation of pulse quality, the proposed device performs efficient high-quality amplification and compression of ultrashort fundamental solitons while it almost completely preserves the soliton nature of the input pulses. Moreover, the performance of the device is insensitive to small variations in the loop length and in the power-splitting ratio of the coupler.

Journal Article↗