Abstract
We demonstrate focusing of the microwave radiation by a planoconcave lens based on photonic crystal superlattice. The superlattice consists of dielectric rods of two different diameters. The structural modulation results in a narrow transmission subband inside the band gap. The subband is characterized by a negative refractive index and high transmission efficiency. This negative refractive index arises from the Brillouin zone folding in the lattice with the composite unit cell. The full width at half maximum of the focal spot of our lens is 0.36λ×0.42λ, which is close to the Abbe limit, and the power enhancement is 2.2.
Original language | English |
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Article number | 124512 |
Journal | Journal of Applied Physics |
Volume | 104 |
Issue number | 12 |
DOIs | |
State | Published - 2008 |