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The article focuses on the proposed usage of 1.3 μm control optical pulses and a 1.3 μm semiconductor optical amplifier (SOA) in picosecond (ps) optical switching of a 1.5 μm active birefringent optical fiber loop filter. Wavelength shift of the transmission/reflection characteristics of the filter was due to the injection of 1.3 μm control signal. Switching time of less than 100 ps is realized by using 1.3 μm gain-switched ps optical pulses.

A method for speeding up the gain recovery time of a semiconductor optical amplifier (SOA) using continuous wave (CW) assist light is examined as a method for improving the response speed and reducing the pattern effect in an all-optical-wavelength conversion method using the cross-gain modulation (XGM) of SOAs. The assist light is input at a transparent wavelength of the SOA gain curve and can effectively and rapidly recover the carrier while suppressing the drop in the gain of the SOA. However, since the SOA transparent wavelength is changed by the carrier density and distribution in the SOA, the optimum condition is believed to greatly affect the SOA operating conditions such as the incident light wavelength, intensity, and propagation direction. In this paper, we theoretically and experimentally examined how the wavelength and the propagation direction of the assist light affect the response speed of the SOA. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 88(5): 10–20, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20131 [ABSTRACT FROM AUTHOR]

Abstract: We propose and experimentally demonstrate the temporal-Talbot-effect (TTE)-based preprocessing for the pattern-effect reduction in the all-optical clock recovery using a semiconductor-optical-amplifier (SOA)-based fiber ring laser (SOA-FRL). The TTE-based preprocessing successfully reduced the pattern effects of the recovered clock pulses, so that the 10-GHz clear optical clock pulses were recovered from a 10-Gbit/s return-to-zero on–off keying (RZ-OOK) pseudo-random bit sequence (PRBS) optical signal. “Peak variation” and “Pattern-dependent intensity noise (PDIN)” were proposed and were utilized as parameters to quantitatively evaluate the pattern effects, from which recovered clock pulses suffer, in the temporal domain and the frequency domain, respectively. Peak variation was reduced from 77.2% to 36.2%, and PDIN was improved from −103dBc/Hz to −110dBc/Hz with the aid of the TTE-based preprocessing. Furthermore, we examined the tolerance of the proposed technique by intentionally deviating the input signal’s bit-rate by ±190Mbit/s (±2% of the bit-rate) from the optimum condition for the TTE. As compared with the PDIN value for the pulse train obtained by the direct injection of the non-processed signal into the SOA-FRL, the PDIN of the recovered clock pulses using the preprocessed signal indicated improvements over the entire measurement range of ±190Mbit/s, which corresponds to the wavelength-dispersion deviation of ±56ps/nm (±4% of the wavelength-dispersion applied to the input signal) from the optimum value. [Copyright &y& Elsevier]