Characterisation of photonic crystals fabricated by holographic lithography
<p>Holographic lithography is a new technique developed for the fabrication of threedimensional photonic crystals in polymer. Four coherent laser beams are interfered to generate a three-dimensionally periodic interference pattern in a film of photoresist. Subsequent processing steps render a...
| Main Authors: | , |
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| Format: | Thesis |
| Language: | English |
| Published: |
2004
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| Subjects: |
| Summary: | <p>Holographic lithography is a new technique developed for the fabrication of threedimensional photonic crystals in polymer. Four coherent laser beams are interfered to generate a three-dimensionally periodic interference pattern in a film of photoresist. Subsequent processing steps render a three-dimensional photonic crystal, whose structure is commensurate with the original interference pattern.</p> <p>Two interference patterns are discussed in detail: a face-centred cubic pattern with a conventional lattice constant of 922<em>nm</em> in air and a face-centred cubic pattern with a conventional cube side of 397<em>nm</em> in air (interference wavelength 355<em>nm</em>). Three types of basis are presented for the interference pattern with a 922<em>nm</em> lattice constant: a righthanded, a left-handed and a non-chiral basis. Photonic crystals have been fabricated with both a chiral and a non-chiral basis and evaluated by scanning electron microscopy. Optical transmission measurements are presented for the non-chiral photonic crystals and are interpreted in both a Bragg scattering model and a photonic bandstructure model. A 'GaAs' and a 'diamond' basis are presented for the interference pattern with a 397<em>nm</em> lattice constant. Photonic crystals have been fabricated with the 'GaAs' basis and evaluated by scanning electron microscopy.</p> |
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