All-Optical Multi-Wavelength Conversion Using Absorption Modulation of an Injection-Locked FP-LD

Abstract

All-optical wavelength converter is a key functional element that enables transparent interoperability, contention resolution, wavelength routing, and, in general, better utilization of the network resources under dynamic traffic patterns in wavelength-division-multiplexed (WDM) optical networks. With those capabilities, all-optical wavelength converter becomes a vital part of optical switching node in all-optical network where switching and routing function are performed in optical domain. Researchers have been making huge effort to find and demonstrate all-optical multi-wavelength conversion schemes such as cross-absorption modulation (XAM) in an electro-absorption modulator (EAM) or cross-gain modulation of amplified spontaneous emission (ASE) spectrum of SOA. However, those schemes experience high crosstalk power penalty, which is proportional to the number of channels. The best one, as we have known so far, is based on injection locking technique. This scheme has several advantageous features, including low input power requirement, large conversion range, capability of logically inverted and non-inverted conversion and cost-effectiveness since it uses a low cost, commercialized Fabry-P$\acute{e}$rot laser diode. In this thesis, an all-optical multi-wavelength converter using absorption modulation of an injection-locked Fabry-Perot laser diode is demonstrated at 2.5Gbps. With the number of probe wavelengths is four, the multi-wavelength converter in experiments can simultaneously support 1, 2, 3, or 4 channels depending on the number of respectively activated probe wavelengths. Especially, the multi-wavelength converter can support both inverted and non-inverted wavelength conversions at once, or support either of them at a time. All converted outputs show high probe power extinction ratios, from 14dB to 16dB; low bit error rate, BER=$10^{-9}$, at the received power $\le$-34dB; and negligible crosstalk power penalties (maximum power penalty=0.358 at B...