Designing and optimizing optical amplifiers to maximize system performance is becoming increasingly important as optical communication systems strive to increase throughput. Offline optimization of optical amplifiers relies on models ranging from white-box models deeply rooted in physics to black-box data-driven and physics-agnostic models. Here, we compare the capabilities of white-, grey- and black-box models on the challenging test case of optimizing a bidirectional distributed Raman amplifier to achieve a target frequency-distance signal power profile. We show that any of the studied methods can achieve similar frequency and distance flatness of between 1 and 3.6 dB (depending on the definition of flatness) over the C-band in an 80-km span. Then, we discuss the models' applicability, advantages, and drawbacks based on the target application scenario, in particular in terms of flexibility, optimization speed, and access to training data.

翻译：随着光通信系统不断追求提升吞吐量，设计和优化光放大器以最大化系统性能变得日益重要。光放大器的离线优化依赖于各类模型，从深植于物理原理的白盒模型，到数据驱动且与物理机制无关的黑盒模型。本文以优化双向分布式拉曼放大器以实现目标频率-距离信号功率分布这一具有挑战性的测试案例为背景，比较了白盒、灰盒与黑盒模型的能力。研究表明，在80公里跨距的C波段内，所有被考察方法均能实现1至3.6 dB（取决于平坦度的定义）的频率与距离平坦度。随后，我们基于目标应用场景（特别是在灵活性、优化速度和训练数据可获取性方面）讨论了这些模型的适用性、优势与局限性。