Dear Sir/Madam,
I am currently working on a beam shaping problem and have referenced the Metalens example provided on the Ansys Lumerical website. In that example, a forward propagating plane wave source was used to obtain a focused beam at a focal length (for instance, 5 micrometers) from the metasurface.
For my specific case, I intend to use a backward propagating source, where the incident light propagates in the negative z-direction. Consequently, I anticipate the beam to be focused at a distance of -5 micrometers. My question pertains to the focal length value: should I input 5 micrometers or -5 micrometers for the backward propagating case? If I input 5 micrometers, the resulting profile would not resemble a converging lens but rather a diverging lens profile.
Could someone please clarify this doubt?
Thank you.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Waves