Wednesday, March 09, 2022

On Characterizing Flat Lenses in Nature Photonics

Jacob Engelberg & Uriel Levy of The Hebrew University, Jerusalem have published a Nature Photonics Comment piece titled "Standardizing flat lens characterization".

The field of flat lens research brings innovative nanophotonic design concepts to the world of macro-optics. However, when evaluating the performance of these lenses a lack of consistency prevents proper comparison of competing technologies. This problem can be solved by using methods developed in industry for conventional lenses.

 

We will focus on the two most basic performance metrics: resolution and signal-to-noise ratio (SNR). The main problems we encountered in the field are the use of full-width at half-maximum (FWHM) as a resolution metric by some authors, despite it being an insufficient metric, and the use of ‘focusing efficiency’ as the sole SNR metric. In a nutshell, our suggestion is to use the modulation transfer function (MTF) as the resolution metric and diffraction efficiency and overall transmission as the SNR metric. These parameters can be characterized both on-axis and off-axis if the flat lens is designed to cover a certain field-of-view (FOV).


Fig. 1 

 


 

Link to full article: https://www.nature.com/articles/s41566-022-00963-7

 

No comments:

Post a Comment

All comments are moderated to avoid spam and personal attacks.