Adjoint shape optimization applied to electromagnetic design.

Area of Science:

• Electromagnetics
• Computational Physics
• Photonics

Background:

• Electromagnetic component design requires sophisticated optimization techniques.
• Previous methods, such as stochastic approaches, can be computationally intensive and slow.
• Efficient inverse design is crucial for advancing photonic integrated circuits.

Purpose of the Study:

• To present an adjoint-based optimization framework for electromagnetic design.
• To demonstrate the efficiency and effectiveness of this method compared to prior approaches.
• To apply the method to a practical silicon photonics device.

Main Methods:

• Embedding commercial Maxwell solvers within a steepest-descent inverse-design algorithm.
• Utilizing the adjoint approach to calculate spatial shape derivatives with only two forward simulations.
• Employing the level set method for geometrical shape parameterization.

Main Results:

• The adjoint design optimization converged much faster than stochastic methods.
• The method operated effectively within a larger design space.
• Successful application to a silicon photonics Y-junction splitter.

Conclusions:

• Adjoint-based optimization offers a significantly faster and more efficient approach for electromagnetic design.
• This method enables the design of complex electromagnetic components with greater speed and within a broader design space.
• The technique is particularly promising for silicon photonics applications.