2027 will be our biggest presence at Photonics West ever!
We teased about it during META 2026 in Dublin (June 2026), we officially released our new MetaStack™ product (September 2026), but at Photonics West 2027 you will trully be able to see and hear all that is now possible in the field of reliably modelling the interactions between multiple metaoptical surfaces in cascade.
Don’t miss it and be sure to visit us at Photonics West 2027, 2-4 February 2027, at booth 2122.
Presentation
Wave based tolerancing analysis of imaging metalens systems
Date: 1 February 2027
Time: 2:40 PM – 3:10 PM PST
Session: Nano-Photonics Modules and Systems
Abstract
Metasurfaces have matured significantly and are now used in high volume. Despite this progress, design of metalens beam shaping and imaging systems relies on approximations. Since meta-surfaces are diffractive by nature these approximations ignore important loss channels. In this contribution we report a wave based framework for modelling systems of many meta-surfaces. Based on this, we analyse the effect of meta-atoms and fabrication defects on the MTF. As an example system we designed compact metalens imagers with a FOV of 90° and f# 2.4. A doublet system with 40nm bandwidth and a singlet system with 4nm bandwidth are compared.
Technical abstract
Metasurfaces have matured significantly and are now used in high volume applications. Despite this progress, design of metalens beam shaping and imaging systems relies on approximations of the wavefront in order to handle them by ray-tracing. Since meta-surfaces operation is diffractive by nature, these approximations ignore important loss channels.
Discrete phase sampling, angle dependence of the meta-atom, and fabrication defects manifest as 0th and higher order diffraction. This results in potentially poor imaging contrast and low signal to noise ratio if not well managed.
In this contribution we present an analysis of the effect of design approximations and fabrication defects on the imaging performance of a doublet metalens system. For this we have developed a wave based framework for modelling systems of many meta-surfaces. Previous work on tolerancing of meta-surfaces has focussed on individual meta-surfaces and basic performance metrics such as focusing efficiency. Our analysis expands on this by modelling the interaction between fabrication imperfections on application relevant and specific metrics like MTF. Additionally our method expands from one to many meta-surfaces. Calculations are performed using PlanOpSim commercial software.
As a system we designed a singlet and doublet meta-surface imager with a FOV of 90°, f# 2.4. The total track length is below 2mm in both cases. The operating spectrum was respectively 938-942 and 920-960nm for the singlet and doublet. Designs were made by raytracing assuming smooth analytical wavefronts. Afterwards these lenses were implemented as metasurfaces using a library of Si meta-atoms on a BK7 wafer and their polychromatic MTF calculated across the FOV. Afterwards we compare the simulated MTF from ray-tracing, wave calculated nominal metasurface and with aberrated meta-atoms.
This method enables to analyze and mitigate the performance loss by diffractive mechanisms in meta-surface systems. It can be straightforwardly expanded to other metalenses and specifications.
