We develop and apply an optimization method to design unidirectional invisibility cloaks. Our method is based on minimizing the forward scattering amplitude of the cloaked object which, by the optical theorem, is equivalent to the total cross section. The use of the optical theorem circumvents the need to evaluate and integrate the scattering amplitude over an angle at each iteration, and thus provides a simpler, more computationally efficient objective function to optimize structures. We implement the approach using gradient descent optimization and present several gradient-permittivity unidirectional cloaks that reduce scattering by metallic targets of different sizes and shapes.

中文翻译：

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利用光学定理逆向设计隐形斗篷

我们开发并应用一种优化方法来设计单向隐形斗篷。我们的方法基于最小化隐身物体的前向散射幅度，根据光学定理，该幅度等于总横截面。光学定理的使用避免了在每次迭代时评估和积分一个角度上的散射幅度的需要，因此提供了一个更简单、计算效率更高的目标函数来优化结构。我们使用梯度下降优化来实现该方法，并提出了几种梯度介电常数单向斗篷，可减少不同尺寸和形状的金属目标的散射。