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Higher order modes in photonic crystal slabs
Roman Gansch1, Stefan Kalchmair, Hermann Detz
1Center for Micro- and Nanostructures, Vienna University of Technology, Floragasse 7, 1040 Vienna, Austria. roman.gansch@tuwien.ac.at
Optics Express
|September 22, 2011
Summary
Researchers investigated higher order modes in photonic crystal slabs. They found resonance shifts in photocurrent spectra, enabling distinction of slab modes and polarization, complementing existing characterization techniques.
Area of Science:
- Photonics
- Condensed Matter Physics
- Materials Science
Background:
- Photonic crystal slabs exhibit unique optical properties due to their periodic nanostructure.
- Understanding higher order modes is crucial for designing advanced photonic devices.
- Resonance shifts in these structures are influenced by mode order and polarization.
Purpose of the Study:
- To investigate higher order modes in photonic crystal slabs.
- To correlate resonance shifts in photocurrent spectra with slab mode order and polarization.
- To present a complementary characterization method for photonic crystal slabs.
Main Methods:
- Fabrication of photonic crystal slab photodetector devices with varying thickness-to-lattice constant ratios.
- Analysis of photocurrent spectra to identify resonance shifts.
- Distinguishing between 0th and 1st order slab modes and polarization based on spectral shifts.
Main Results:
- Observed blue-shift of resonances compared to ideal 2D photonic crystals.
- Demonstrated successful differentiation of 0th and 1st order slab modes via photocurrent spectra.
- Established a link between resonance shifts and polarization effects.
Conclusions:
- The study successfully characterized higher order modes in photonic crystal slabs.
- Photocurrent spectra analysis provides a viable method for distinguishing mode orders and polarization.
- This technique offers a valuable alternative to photonic band structure mapping for slab characterization.
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