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Transformation-optical design of adaptive beam bends and beam expanders
M Rahm1, D A Roberts, J B Pendry
1Department of Electrical and Computer Engineering, Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, NC 27708, USA. marco.rahm@duke.edu
Optics Express
|July 24, 2008
Summary
We designed adaptive beam bends and splitters using coordinate transformations, achieving reflectionless surfaces. These reconfigurable metamaterials offer tunable angles for advanced optical devices.
Area of Science:
- Optics and Photonics
- Metamaterials Science
- Electromagnetism
Background:
- Transformation optics enables novel electromagnetic devices.
- Designing reflectionless optical components is a key challenge.
- Metamaterials offer unique electromagnetic properties.
Purpose of the Study:
- To design adaptive beam bends and splitters with arbitrary angles.
- To achieve reflectionless performance at device surfaces.
- To explore the potential of reconfigurable metamaterials for tunable optics.
Main Methods:
- Finite embedded coordinate transformations were employed for device design.
- Full-wave simulations using the finite-element method validated performance.
- Analysis of relative permittivity and permeability values was conducted.
Main Results:
- Reflectionless adaptive beam bends and splitters were successfully designed.
- Moderate and achievable material parameters (permittivity and permeability) were identified.
- The concept of dynamically tunable angles for reconfigurable metamaterials was demonstrated.
- An adaptively adjustable transformation-optical beam expander/compressor was presented.
Conclusions:
- Finite embedded coordinate transformations provide a viable design route for advanced optical components.
- The developed devices are suitable for applications requiring tunable beam manipulation.
- Pure transformation optics may not yield reflectionless beam expanders/compressors.
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