How does FDTD simulate light from finite distant objects like zemax

- January 22, 2024 at 12:08 pm
  
  He HouTu
  Subscriber
  
  I wanted to simulate the imaging process in FDTD like zemax, where the object distance is finite, so the light is emitted from a single point. How does I set the source, and simulate the imageing condition with difference field of view like zemax?
- January 23, 2024 at 9:10 am
  
  Niki Papachristou
  Ansys Employee
  
  Hi He,
  Thank you for reaching out to us! I am kind of confused on what you want to achieve here. Lumerical's FDTD solver is used for component level simulations with sizes comparable to the wavelength, while Zemax Optic Studio is used for larger components where geometric optics equations apply. Hence, if you want to do an image analysis I would suggest to keep using Zemax. Is there anything else that you would like to simulate that I am missing?
  Kind Regards,
  Niki
  - January 23, 2024 at 11:40 am
    
    He HouTu
    Subscriber
    
    Dear Niki,
    I am grateful to your reply, but I still have a questions. I means the scale for lens is wavelength order, for example the radius is 50um. How can I reappear the picture of my question? The lights come from the source which object distance is finite, and be focused. I don't know how to set the source of this condition.
    Kind Regards,
    He HouTu
- January 23, 2024 at 12:02 pm
  
  Niki Papachristou
  Ansys Employee
  
  Hi He,
  Thank you for coming back to us, I believe your simulation is fairly advanced. Having a second look on your image attached, I see that you want to simulate a metalens. Is the radius (50μm) that you are reffering to, the radius of a nanorod on your metalens? Or are you talking about a radius of curvature of a lens? I think in your case you will need to use both lumerical's solvers FDTD/RCWA and AZOS. We have already a couple of examples on our applications gallery: Small-Scale Metalens – Field Propagation, Large-Scale Metalens – Ray Propagation that should be very helpful for you.
  Kind Regards,
  Niki
  - January 23, 2024 at 12:12 pm
    
    He HouTu
    Subscriber
    
    Dear Niki,
    I am really grateful to your reply again. I means the radius(50um) of metalens. I have learn the example in your said, but I don't know how to set the source of this condition, which the lights come from the source which object distance is finite and be focused.
    Kind Regards,
    He HouTu
- January 23, 2024 at 1:57 pm
  
  Niki Papachristou
  Ansys Employee
  
  Hi He,
  In your case I would start my simulation with a simple plane wave and then move to more complecated cases.
  Kind Regards,
  Niki
  - March 3, 2024 at 1:08 pm
    
    He HouTu
    Subscriber
    
    Dear Niki, thank you very much. Do you have some new idea about such a simulation? If you have some idea, please give me some advices.
    Kind Regards,
    He HouTu