Analysis of Different Wavelength Injection Techniques in Bidirectional Wavelength Division Multiplexed Passive Optical Networks

In this paper, a combination of different wavelength injection techniques is demonstrated in a bidirectional WDM PON's implementation using arrayed waveguide grating. Wavelength reusable ONU's are provided with fiber bragg grating at particular wavelength, so that it reflects particular wavelength and transmits the remaining power, which is re-modulated as upstream by LiNbO3 modulator. Self seeding based ONU's are provided with reflective semiconductor optical amplifier, so that it not only function as amplifier, but also as a modulator for upstream generation(no need of local sources). Externally wavelength injected ONU's are provided with local source for upstream generation. The integration of all three wavelength injection techniques makes a true next generation PON technologies. The performance of implemented system has been analyzed on the basis of Min-log of BER versus OSNR, Min-log of BER versus received power. The performance of wavelength reusable based ONU's are close to externally injected ONU's performance in both downstream and upstream, so that it can be used in place of externally wavelength injected with link-length trade-off. Self-seeding based ONU's performance is close to externally wavelength injected ONU's performance below 50Km link-length in both downstream and upstream, so that it can be used in place of externally wavelength injected with upstream data rate trade-off.