All-optical wavelength conversion for optical communication systems.

摘要

The conventional techniques for all-optical wavelength conversion require high optical power for achieving adequate nonlinear phase shift. In this thesis, we describe the theoretical and experimental results for the low power all-optical wavelength conversion by employing a new technique of dual-wavelength injection locking an Fabry-Perot (FP) laser diode. The method is simple to implement by using a commercially available double-channel planar-buried heterostructure (DC-PBH) FP laser.; Experiments demonstrated that this dual-wavelength injection-locking wavelength converter can perform low power wavelength conversion (∼0.46mW) of 3Gb/s 231-1 pseudorandom signal with a wavelength range of 38nm (from 1526nm to 1564nm) in more than 10dB extinction ratio. The wavelength converted signals were chirp-reduced and can propagate through 25km to 50km (without amplification) with bit-error rates of the order 10−10 s−1 and 10−9s−1 respectively, thus fulfils the standard for 3R repeater distance of 40km.; Some new applications are proposed and demonstrated by modifying this dual-wavelength injection-locking wavelength converter, these are (i) all-optical device for time-division demultiplexing with simultaneous wavelength conversion, (ii) all-optical one-to-three wavelength conversion, (iii) high frequency pulse-train generation by stimulated relaxation oscillation, (iv) wavelength tunable 10Gb/s chirp reduced pulse generation, and (v) all optical modulation.; Furthermore, the theory of chirped pulse self-phase modulation (CPSPM) was proposed in this thesis. By employing this CPSPM technique, a low power scheme for the measurements of nonlinear index n₂ in dispersion-shifted fiber (DSF) and an InGaAsP/InP waveguide were demonstrated. Since this method can resolve small nonlinear phase shift by self-phase modulation, the peak power required for measuring the 1.6km DSF was only 245mW and the corresponding maximum phase shift was 0.3π. The n₂ of DSF measured by this CPSPM was 2.634 × 10−20 m2/W compared to the reported value 2.6 × 10−20m2/W. Therefore this method can be used for the design of wavelength converter that employing nonlinear effect (e.g. nonlinear optical loop mirror NOLM). (Abstract shortened by UMI.)