Biomedical subjects
Publications and source records attributed to Xianyu Ao.
A two-dimensional metallo-dielectric photonic crystal of negative refraction was designed for the application of polarization beam splitters. To match the refractive index of air, the effective refractive index of the designed photonic crystal is -1 for TE polarization and +1 for TM polarization. Two types of polarization beam splitter are presented.
A simple subwavelength focusing system formed by a straight or bent multimode waveguide is investigated numerically. The simulation results indicate that an appropriately designed multimode waveguide can focus the outgoing waves of a point source and form an image with a full width at half-maximum of less than half a wavelength in the near-field area at the other side of the waveguide. The physical mechanism of the subwavelength focusing for this imaging system is explained.
A three-dimensional bicontinuous photonic crystal of a bcc lattice with all-angle negative refraction that can be achieved at optical frequencies by interference lithography is proposed. A numerical simulation of the focusing imaging of a slab of this crystal was performed to verify the property of all-angle negative refraction. The dependence of the negative-refraction frequency range on the threshold of photoresist development and on the dielectric constant is also discussed.
General properties of N x M self-images in a strongly confined rectangular waveguide are given. Analytical formulas are derived for the positions, amplitudes, and phases of the N x M images at the end of multimode interference section. The formulas are verified with numerical simulation of a three-dimensional semivectorial beam propagation method.