Once the near-field for the metalens is exported to a. Step 4: Propagation of imported beam in OpticStudio Then, the approach will be applied to a much larger metalens based on the optimized target phase in OpticStudio. We will use a spherical metalens with a small radius to verify the accuracy of the “indirect” approach.

A detailed description of these approaches will be provided in the corresponding step in the “Run and Results” section. This avoids the time-consuming simulation of the full lens and hence can be much more efficient than the direct simulation approach. Reconstruction of full fields: The near-field/far-field of the full metalens can be reconstructed with a script using the nearfield library from Step 2. ZBF file for further propagation in the Ansys OpticStudio. The nearfield from the simulation can be used for far-field analysis and exported to a. While this approach is more straightforward, it can pose challenges in terms of memory and simulation time, especially for larger metalens. radius is built from step 2, there are two approaches available for the design and analysis of the full metalens:ĭirect simulations: Construct and simulate the full metalens in FDTD based on the target phase profile and the phase vs. radius results are then saved for the next steps. The height that gives the desired transmission and phase properties is chosen. In this step, we sweep the height and radius of the nanorod and obtain the transmission, phase, and near-field. Step 2: Unit cell simulations with RCWA – Height and radius sweep However, we can design the ideal phase mask in OpticStudio using ray tracing and optimization capabilities for more complex systems where analytical solutions don't exist or would be hard to calculate. For the most common lens types, such as spherical or cylindrical elements, we can use the known analytical solutions. The first step is to define the target phase profile for the metalens.

With the knowledge of the phase in terms of the geometry parameters, it is possible to create a metalens with an arbitrary phase profile by placing the meta-atoms at the necessary positions. By adjusting the geometry of these unit cell elements, one can modify the phase changes experienced by the propagating field. Metalenses consist of carefully arranged 'unit cells' or 'meta-atoms' with sub-wavelength structures. Understand the simulation workflow and key results The design is verified in Ansys RCWA (Rigorous Coupled-Wave Analysis) and OpticStudio through near- and far-field analyses. The radius and the arrangement of the nanorods are tailored to create a desired phase profile on the metalens surface. The goal of this example is to design a diffractive metalens consisting of cylindrical nanorods.

Lumerical fdtd examples