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To support multimedia services with different discrete bit-rate requirements, families of multilength optical codes, such as the carrier-hopping prime code (CHPC), extended CHPC, and multiwavelength optical orthogonal code, were recently constructed for wavelength-time optical code-division multiple-access (O-CDMA). In this paper, the performances of these multilength optical codes in a multimedia O-CDMA system with a variable-weight operation are analyzed. Our study shows that short-length codes generate stronger interference than long-length codes. This supports services prioritization in O-CDMA. Our study also shows that code weight is a more important factor than code length in determining code performance. [ABSTRACT FROM AUTHOR]

Puncturing is studied as a physical layer mechanism for efficiently transmitting datastreams containing bits of unequal priority via wavelength-time optical code-division multiple access. Puncturing increases system capacity, while ensuring that important bits are received with low bit-error rate. [ABSTRACT FROM AUTHOR]

Abstract: We present a novel design for all-optical conversion from wavelength-hopping time-spreading to non-return-to-zero format using wavelength converters based on semiconductor optical amplifiers. The multi-pulse nature of the wavelength-hopping time-spreading signal is utilized to achieve efficient, high-performance format conversion without pulse replication. The operation is demonstrated with a power penalty of 1dB. A novel, complete design for interfacing wavelength-hopping time-spreading networks to WDM networks is also presented. [Copyright &y& Elsevier]

Abstract: We present a complete mathematical formalism for a rapidly reconfigurable gated timeslot tuner based on a serial feed-forward structure. This gated serial timeslot tuner has been a key component for various demonstrations including a 100 Gb/s photonic switched interconnect [K.-L. Deng, R.J. Runser, P. Toliver, I. Glesk, P.R. Prucnal, J. Lightwave Technol. 18 (2000) 1892]. Design constraints for the proper operation of the interconnect are developed. Methods to predict feasible multicast combinations and control patterns required for driving the timeslot tuner are presented in terms of a two-dimensional (2D) contour map. [Copyright &y& Elsevier]

Abstract: Sagnac interferometric loops with a semiconductor optical amplifiers (SOA) have found important applications for optical signal processing and communication networks. We derive a new description of the transmission of an SOA-based Sagnac loop by including the influence of loop birefringence. Based on this new description, we theoretically analyze and experimentally demonstrate NRZ wavelength conversion using a Sagnac loop with an SOA at asymmetric position. We also show that the converted signal with an SOA-based Sagnac loop has lower pattern dependent effect and smaller power penalty compared with the converted signal using cross gain modulation effect. [Copyright &y& Elsevier]

We present a complete analysis of the operation of an ultra-fast tunable parallel optical delay line. Based on our analysis, we propose and experimentally demonstrate a generalized serial–parallel delay line structure, which provides better scalability with respect to the number of timeslots. The delay line uses one electro-optic modulator and an all-fiber delay lattice. We also present a discussion on two important performance measures of this delay line – the tuning speed and the optical power loss. [Copyright &y& Elsevier]

In this paper, a new family of two-dimensional (2-D) wavelength-hopping time-spreading codes, which employs wave-length hopping algebraically under prime-sequence permutations on top of time-spreading optical orthogonal codes, is studied and analyzed. Different from other 2-D codes, our new codes allow the number of wavelengths and code length to be chosen independently and, at the same time, the code cardinality is a quadratic function of the number of wavelengths without sacrificing the maximum cross-correlation value (i.e., still at most one). They are particularly suitable for high bit-rate optical code-division multiple-access systems with broadband mode-locked lasers, in which the number of time slots is very limited, and system capacity can only be grown by increasing the number of wavelengths, rather than code length. Finally, a novel wavelength-aware detector for wavelength-hopping time-spreading codes is discussed and shown to provide improved code performance. [ABSTRACT FROM AUTHOR]

We demonstrate return-to-zero (RZ) to non-return-to-zero (NRZ) optical data format conversion using a duplicator and a wavelength converter. Multiple copies of the input RZ pulses are made within bit periods, and sent to a wavelength converter to generate optical NRZ data format. The eye diagram of converted NRZ optical signal shows reduced ripples. [Copyright &y& Elsevier]