Effect of side-mode suppression ratio on the performance of self-seeded gain-switched optical pulses in lightwave communications systems

Abstract

Abstract-The side-mode suppression ratio (SMSR) of selfseeded gain-switched optical pulses is shown to be an extremely important factor for the use of these pulses in optical communications systems. Experiments carried out involving pulse propagation through dispersion-shifted fiber and a bandpass optical filter demonstrate that, for SMSR values of less than 25 dB, the buildup of noise due to the mode partition effect may render these pulses unsuitable for use in optical communications systems.

Electro-Optical Generation and Distribution of Ultrawideband Signals Based on the Gain Switching Technique

“…Figure 4(a) shows that the GS FP-LD can be used to achieve error-free performance ͑BERϽ 10 −9 ͒ while transmitting over fiber lengths up to 450 m. The degraded performance over 650 m is mainly due to mode partition noise (MPN). Dispersion in the fiber causes the fluctuations of the energy between the longitudinal modes of the FP-LD to be translated into intensity fluctuations on the transmitted optical signal, thus reducing its signal-to-noise ratio [18]. Another contributory factor to the performance degradation is the amplified spontaneous emission (ASE) from the EDFA (because no ASE removal filter is used).…”

Self-Seeding of a Gain-Switched Integrated Dual-Laser Source for the Generation of Highly Wavelength-Tunable Picosecond Optical Pulses

“…Provided that the optical signal reinjected into the laser arrives during the buildup of an optical pulse in the FP laser, then a single-moded output pulse is obtained. An important charac- teristic of these Self-Seeded Gain-Switched (SSGS) sources is the variation in the side-mode suppression ratio (SMSR) as the wavelength is tuned [6], as this may ultimately affect their usefulness in optical communication systems. In particular, recent work has demonstrated that, as the number of channels in a WDM system using SSGS pulse sources increases, the specifications on the required SMSR, due to cross-channel interference, may become very stringent [7].…”

Highly coherent picosecond pulse generation with sub-ps jitter and high SMSR by gain switching Discrete Mode laser diodes at 10 GHz line rate

“…Unfortunately while low cost and simplicity are among the numerous advantages of this technique, it does suffer from some drawbacks, such as side mode suppression ratio (SMSR) degradation and relatively large temporal jitter. While these shortcomings have been overcome by self seeding [3] or external light injection [4], such corrective measures not only increase the cost and complexity of the pulse generation technique but also can lead to unstable operation.…”

“…Unfortunately while low cost and simplicity are among the numerous advantages of this technique, it does suffer from some drawbacks, such as side mode suppression ratio (SMSR) degradation and relatively large temporal jitter. While these shortcomings have been overcome by self seeding [3] or external light injection [4], such corrective measures not only increase the cost and complexity of the pulse generation technique but also can lead to unstable operation.In this paper, we investigate gain switching of single mode Discrete Mode laser diodes [5] and demonstrate simple generation of highly coherent picosecond pulses at 10GHz. We also compare the gain switching performance of DM lasers with that of conventional DFB laser diodes.…”