Packet clock recovery at 40 Gb/s and beyond, using a Fabry-Pérot filter and an optical power limiter based on a bismuth oxide fibre

In the present paper, the authors demonstrated successful CR from short optical packets at 40 Gb/s, using a recently introduced technique that allows in principle for operation at ultra-high bit rates far beyond 40 Gb/s. The technique is based on the previously reported scheme that uses a Fabry-Perot Filter (FPF) for producing a clock resembling signal, followed by an optical power limiter in order to remove the strong peak power variation of the FPF´s output, and thus provide a clock signal of high quality. Unlikely to the previous implementations of the scheme, the power limiting functionality is not based on semiconductor-based devices, but rather on the use of a nonlinear fiber, erasing in principle any operational bit rate limitations of the scheme.