This book presents how metasurfaces are exploited to develop new low-cost single sensor based multispectral cameras. Multispectral cameras extend the concept of conventional colour cameras to capture images with multiple color bands and with narrow spectral passbands. Images from a multispectral camera can extract significant amount of additional information that the human eye or a normal camera fails to capture and thus have important applications in precision agriculture, forestry, medicine, object identifications, and classifications. Conventional multispectral cameras are made up of multiple image sensors each externally fitted with a narrow passband wavelength filters, optics and multiple electronics. The need for multiple sensors for each band results in a number of problems such as being bulky, power hungry and suffering from image co-registration problems which in turn limits their wide usage. The above problems can be eliminated if a multispectral camera is developed using one single image sensor.

Autorentext

Xin He received his M.Eng. and Ph.D degrees from the University of Melbourne, Australia, in 2016 and 2020 respectively. His research interests include metasurface, nano-optics and spectral imaging. He obtained advanced skills on Micro/Nano Fabrication and COMSOL Multiphysics with RF and optics model. Except publications, he also created a prototype of a multispectral image sensor with 6 bands in the visible and infrared bands for commercial exploitation.

Paul Beckett received his B. Eng. degree in Communication Engineering, M. Eng. and Ph.D. degrees from RMIT University, Melbourne, Australia, in 1975, 1984, and 2007, respectively. Recently retired after an academic career spanning 38 years, he is currently an Honorary Associate Professor with the School of Engineering, RMIT University where his research interests include the design and simulation of nanoscale architectures and the mixed-signal modeling of asynchronous reconfigurable circuits.

Ranjith R Unnithan is a Research Group Leader and Senior Lecturer at the Department of Electrical and Electronic Engineering, the University of Melbourne, Melbourne, VIC, Australia. He is also Director of sensor research at Hort-Eye Pty Ltd., Melbourne. He received his Ph.D. degree in electrical engineering from the University of Cambridge, Cambridge, U.K., in November 2011. His research areas span CMOS image sensors, AR displays, sensor electronics for biomedical applications, drone-based sensors and applications, multispectral thermal cameras, and nanophotonic engineering.

Inhalt

1. Front Matter

   2. Introduction

   a. Conventional Colour Filters and Image Sensors

   b. Conventional Multispectral Imaging (MI) sensor Systems

   i. Prism/Beam Splitter

   ii. Multilayer Coating based Filters

   1. Fabry-Pérot (FP) Etalon

2. Photonic Bandgap techniques

   c. Applications of MI

   d. Limitations of the conventional Multispectral sensor systems

   e. Summary and Conclusions

   3. Nanostructured Metasurface-based Optical Filters for MI applications a. Dielectric Guided-mode-resonance Filter (GMRF)

   b. Silicon Nanowire based filters

   c. Metallic Plasmonic Surface Filters

   i. Nanoslit Gratings

   ii. Nanohole Arrays

   iii. Nanoparticle Structures

   iv. Metallic Apertures

   d. Other techniques

   e. Summary and Conclusions

   4. Simulation and Fabrication Techniques for Nanoscale Metasurfaces

   a. Geometry, Structures and Materials

   b. Boundary Conditions

   c. Meshing

   d. Materials Considerations e. Fabrication techniques

   f. Summary and Conclusions

   5. Transmission Enhancement in Coaxial Hole Array Based Plasmonic Color Filters

   a. Introduction

   b. Simulation Model and Optimization Method c. Results and Discussion

   d. Summary and Conclusions

   6. Single Sensor based Multispectral Sensor Examples using Metasurfaces

   a. CMY Camera using Nanorod Filter Mosaic

   b. Multispectral Imaging Camera using a Narrow Spectral Band Colour Mosaic c. Hybrid Color Filters

   d. Summary and Conclusions

   7. Concluding Remarks