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Design and Characterization Methodology for Efficient Wide Range Tunable MEMS Filters
Published on: February 4, 2018
Using low-loss phase-change materials for mid-infrared antenna resonance tuning
Ann-Katrin U Michel1, Dmitry N Chigrin, Tobias W W Maß
1I Institute of Physics (IA), RWTH Aachen University, 52056 Aachen, Germany.
Nano Letters
|June 8, 2013
Summary
Aluminum nanoantennas show tunable resonance frequencies by altering the refractive index of phase-change materials. This method avoids resonance damping and achieves significant frequency shifts for mid-infrared applications.
Area of Science:
- Nanophotonics
- Materials Science
- Optical Engineering
Background:
- Aluminum nanoantennas exhibit plasmonic resonances sensitive to their dielectric environment.
- Phase-change materials (PCMs) offer a large, reversible change in refractive index between amorphous and crystalline states.
- Mid-infrared (MIR) applications require materials with low optical loss.
Purpose of the Study:
- To demonstrate the tuning of aluminum nanoantenna resonance frequencies using phase-change materials.
- To investigate different configurations of nanoantennas relative to the PCM layer.
- To evaluate the performance of PCMs for tunable nanophotonic devices.
Main Methods:
- Fabrication of aluminum nanoantennas on and within phase-change material layers.
- Optical characterization in the mid-infrared spectral range.
- Analysis of resonance frequency shifts and full-width at half-maximum (FWHM) based on refractive index changes.
Main Results:
- Significant tuning of resonance frequency observed across different configurations (antennas above, inside, or below PCM).
- Maximum resonance shift of 19.3% achieved due to the large refractive index change of PCMs.
- Negligible imaginary part of PCM permittivity in the MIR range prevented resonance damping.
- Tuning figure of merit (FOM) reached 1.03.
Conclusions:
- Phase-change materials are effective for tunable nanoantenna resonances in the mid-infrared.
- The proposed method allows for both red and blue shifting of resonance frequencies.
- This approach offers a promising route for developing tunable optical devices and sensors.
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