Automatic wavelength allocation method using Rayleigh backscattering for a WDM-PON with tunable lasers

We propose an automatic wavelength control method using Rayleigh backscattering in a feeder fiber for tunable lasers employed in a wavelength-division multiplexing passive optical network. We demonstrate two realization methods, maximizing backscattered power and maximizing the second harmonic component with wavelength modulation. We analyze their limiting factors and impacts on the system performance. We use a VCSEL as a low-cost tunable light source.