Biomedical subjects

Curtis R Menyuk

Publications and source records attributed to Curtis R Menyuk.

5 recordsLinked to original sources

PubMed2006

Probabilistic model of nonlinear penalties due to collision-induced timing jitter for calculation of the bit error ratio in wavelength-division-multiplexed return-to-zero systems.

We introduce a fully deterministic, computationally efficient method for characterizing the effect of nonlinearity in optical fiber transmission systems that utilize wavelength-division multiplexing and return-to-zero modulation. The method accurately accounts for bit-pattern-dependent nonlinear distortion due to collision-induced timing jitter and for amplifier noise. We apply this method to calculate the error probability as a function of channel spacing in a prototypical multichannel return-to-zero undersea system.

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PubMed2006

Impact of interstitial air holes on a wide-bandwidth rejection filter made from a photonic crystal fiber.

We have investigated the spectral properties of a band rejection filter made with a long-period fiber grating written in photonic crystal fiber that has interstitial air holes. Experiments showed that only one mode was coupled strongly to the fundamental core mode over a 600 nm spectral range. The central wavelength of the filter could be tuned over that range without being appreciably affected by any other mode. By using the multipole method, we found that the interstitial air holes of the photonic crystal fiber played a critical role in limiting the number of modes that could strongly interact with the fundamental mode and in obtaining well-separated resonance peaks. Excellent agreement between theory and experiment was obtained.

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PubMed2006

Asymptotic analysis of collision-induced timing shifts in return-to-zero quasi-linear systems with predispersion and postdispersion compensation.

An asymptotic method for calculating the collision-induced frequency and timing shifts for quasi-linear pulses in return-to-zero, wavelength-division multiplexed systems with predispersion and postdispersion compensation is developed. Predictions of the asymptotic theory agree well with quadrature and direct numerical simulations. Using this theory, computational savings of many orders of magnitude can be realized over direct numerical simulations.

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PubMed2005

Calculation, characterization, and application of the time shift function in wavelength-division-multiplexed return-to-zero systems.

We calculate the time shift function for collisions of pairs of pulses in different channels in a prototypical return-to-zero wavelength-division-multiplexed system with dispersion management and precompensation and postcompensation. Once the time shift function is known, the impairments that are due to collision-induced timing jitter can be rapidly determined. We characterize the shape of this function and determine how it scales with the initial pulse separation in time and with channel separation in wavelength. Finally, we apply it to the calculation of the worst-case time shift.

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PubMed2003

Use of multicanonical Monte Carlo simulations to obtain accurate bit error rates in optical communications systems.

We apply the multicanonical Monte Carlo (MMC) method to compute the probability distribution of the received voltage in a chirped return-to-zero system. When computing the probabilities of very rare events, the MMC technique greatly enhances the efficiency of Monte Carlo simulations by biasing the noise realizations. Our results agree with the covariance matrix method over 20 orders of magnitude. The MMC method can be regarded as iterative importance sampling that automatically converges toward the optimal bias so that it requires less a priori knowledge of the simulated system than importance sampling requires. A second advantage is that the merging of different regions of a probability distribution function to obtain the entire function is not necessary in many cases.

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