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Photonic structure designs based on optimization algorithms provide superior properties compared to those using intuition-based approaches. In the present study, we numerically and experimentally demonstrate subwavelength focusing of light using wavelength scale absorption-free dielectric scattering objects embedded in an air background. An optimization(More)
We propose a simple realization of a 2-dimensonal (2D) PT-symmetric photonic structure: a honeycomb arrangement of alternating cylinders with gain or loss in a dielectric background. The structure provides a periodic modulation of the refractive index on the wavelength scale, which combined with an anti-symmetric gain/loss distribution on the same scale,(More)
There have been huge efforts performed on the study of photonic crystals due to their potential to manipulate the flow of light waves at the optical domain. One of the precious features of the photonic crystals is that they have photonic band gaps, i.e. frequency bands in which optical modes are suppressed to exist. The creation of complete photonic band(More)
Photonic crystal waveguides supporting band gap guided modes hold great potential to tailor the group velocity of propagating light. We propose and explore different wavelength demultiplexer design approaches that utilize slow light concept. By altering the dielectric filling factors of each waveguide segment, one can show that different frequencies can be(More)
In this paper, we propose a novel photonic crystal sensor based on refractive index sensing method. The proposed photonic crystal sensor design has a T-shaped sensing slot region to inject bio-material samples with different refractive index values between 1.00 and 1.35. The corresponding highest refractive index unit (RIU) sensitivity of the designed(More)
We present the study on the manipulation of light operating at the semi-Dirac frequency using low-symmetric photonic crystals with C<sub>2</sub> symmetry. A square unit cell of rectangular dielectric rod comprise the semi-Dirac point at the k = 0, where photonic crystal (PC) behaves as either nearly zero-index medium (ZIM) or epsilon near zero (ENZ) medium(More)
In this manuscript, we propose the design of an inhomogeneous artificially modeled graded photonic crystal (PC) medium to control and enrich the polarization insensitive focusing ability of light by using annular type all-dielectric materials. To obtain the graded annular PC structure, the lattice spacing along the transverse direction is modulated(More)
In this paper, differential evolution (DE) optimization algorithm is applied to design sub-wavelength focusing PCs structure for the first time to the best of our knowledge. For this purpose, the transverse cross section of the input beam is spatially shaped by optimized PC structure. Strong focusing of beam with FWHM equal to &#x03BB;/5 and with suppressed(More)
In this article, light localization inside woodpile photonic crystal made of stacks of parallel dielectric rods is numerically and experimentally investigated. The light localization phenomena is achieved by tailoring the structural parameters in the way that a propagating beam is gradually slowed down and finally stopped at a wavelength-dependent position(More)
We numerically investigate the design of a wavelength de-multiplexer based on a tapered photonic crystal waveguide. The tapered waveguide is generated by reducing the width of the channel which, in turn, provides a gradual change in the effective index for the guided modes. Depending on the wavelength, the grading effect enables the propagating beam to be(More)