Unrepeatered Optical Systems Design based on Iterative Channel Pre-Emphasis Optimization

An optimization method is proposed to design unrepeatered optical systems based on distributed Raman and remotely pumped optical amplification. The pumping powers and wavelengths, channels allocation, and remote amplifier's Erbium-doped fiber length and position are optimized by taking into account the link's systemic performance aiming to maximize the equalized optical signal-to-noise ratio (OSNR) at the receiver. An iterative algorithm to allow the sequential design of each element of the unrepeatered system independently is proposed, reducing the computational effort and avoiding its convergence to an optimum local solution. Employing the proposed method, an unrepeatered optical link encompassing both distributed Raman amplification and remotely pumped amplifiers was designed, showing an equalized received OSNR improvement of about 0.6 dB in comparison with a straightforward optimization algorithm. In practical applications, the OSNR gain in system performance can be converted into improvements in link reach and capacity.