Marcelo Davanco

The complex Bloch bands of a 2D plasmonic crystal displaying isotropic negative refraction

The propagation characteristics of a subwavelength plasmonic crystal are studied based on its complex Bloch band structure. Photonic crystal bands are generated with an alternative 2D Finite Element Method formulation in which the Bloch wave problem is reduced to a quadratic eigenvalue system for the Bloch wavevector amplitude k. This method constitutes an efficient and convenient alternative to nonlinear search methods normally employed in the calculation of photonic bands when dispersive materials are involved. The method yields complex wavevector Bloch modes that determine the wave-scattering characteristics of finite crystals. This is evidenced in a comparison between the band structure of the square-lattice plasmonic crystal and scattering transfer-functions from a corresponding finite crystal slab. We report on a wave interference effect that leads to transmission resonances similar to Fano resonances, as well as on the isotropy of the crystals negative index band. Our results indicate that effective propagation constants obtained from scattering simulations may not always be directly related to individual crystal Bloch bands.

Interferometric characterization of a sub-wavelength near-infrared negative index metamaterial.

Negative phase advance through a single layer of near-IR negative index metamaterial (NIM) is identified through interferometric measurements. The NIM unit cell, sub-wavelength in both the lateral and light propagation directions, is comprised of a pair of Au strips separated by two dielectric and one Au film. Numerical simulations show that the negative phase advance through the single-layer sample is consistent with the negative index exhibited by a bulk material comprised of multiple layers of the same structure. We also numerically demonstrate that the negative index band persists in the lossless limit.

Organic Photodetector Focal Plane Arrays Fabricated on Hemispherical Substrates by Three-Dimensional Stamping

We demonstrate a new approach to print organic photodetector arrays on 3D transparent plastic substrates. A 15x15 matrix with a feature size of 500 mum is fabricated, with dark current density is 3.1 muA/cm at -IV.

A subwavelength near-infrared negative index material

A single layer of a subwavelength negative index material (NIM) operating at a wavelength of 1 μm is demonstrated. The geometrical parameters of the nanostructure are determined by characterizing its optical transmission spectrum. We show through photonic band calculations that these parameters give rise to a negative index in a corresponding bulk NIM. The fabrication inaccuracies in the dielectric spacer thickness that are likely to be introduced in a prism composed of multiple layers of this structure are shown through full-wave simulations to be within a range that preserves its negative refractive behavior.

Hemispherical focal plane detector arrays

We demonstrate a 10 kilopixel passive matrix focal plane array consisting of (40mum)2 organic double heterojunction photodetectors on a 1cm radius plastic hemisphere that mimics the size and architecture of human eye.

A heterogeneous III-V/Si3N4 quantum photonic integration platform (Conference Presentation)

Photonic integration is an enabling technology for photonic quantum science, offering greater scalability, stability, and functionality than traditional bulk optics. Here, we describe a scalable, heterogeneous III-V/silicon integration platform to produce Si3N4 photonic circuits incorporating GaAs-based nanophotonic devices containing self-assembled InAs/GaAs quantum dots. We demonstrate pure single-photon emission from individual quantum dots in GaAs waveguides and cavities - where strong control of spontaneous emission rate is observed - directly launched into Si3N4 waveguides with > 90 % efficiency through evanescent coupling. To date, InAs/GaAs quantum dots constitute the most promising solid state triggered single-photon sources, offering bright, pure and indistinguishable emission that can be electrically and optically controlled. Si3N4 waveguides offer low-loss propagation, tailorable dispersion and high Kerr nonlinearities, desirable for linear and nonlinear optical signal processing down to the quantum level. We combine these two in an integration platform that will enable a new class of scalable, efficient and versatile integrated quantum photonic devices.

A heterogeneous III-V / Si_3N_4 quantum photonic integration platform

We develop a heterogeneous III-V/Si3N4 integration platform for photonic integrated circuits incorporating on-chip, InAs quantum dot-based single-photon sources.

A Subwavelength Near-Infrared Negative Index Material

A near-infrared negative index material is demonstrated. The index calculated from a monolayer is verified by band calculations to be a bulk property. Full-wave simulations of a prism made of the structure show negative refraction.

Nanofabrication and Characterization of Subwavelength Metamaterials for Negative-index Propagation at Near-infrared Wavelengths

We describe the nanofabrication for subwavelength optical metamaterials with negative-index propagation at wavelengths near 900 nm. Experimental and theoretical results are discussed.