A Subwavelength Plasmonic Waveguide Filter with a Ring Resonator

The transmission characteristics of the electromagnetic wave are numerically investigated in two-dimensional compound plasmonic structures composed of two straight subwavelength metal-insulator-metal (MIM) waveguides and a ring resonator. The two straight MIM waveguides situate on both sides of the ring resonator, and the MIM waveguide of the outgoing side has a positional angular deviationθrelative to the MIM waveguide of the incoming side. The results show that the filtering performances of the asymmetric structures(θ≠0∘)are greatly improved in comparison with the symmetric structure(θ=0∘). For most of the asymmetric structures, there is a transmission minimum at the slightly bigger wavelength than one at which the transmission peak appears for the symmetric structures, and there is still a transmission peak at the wavelength of the transmission peak of the symmetric structures. Moreover, the difference between the transmission peak and valley is increased, and the breadth of the transmission peak becomes narrow.

Distribution of DVB-C Channels over an Externally Modulated Optical Link

In this paper, we will study, via simulation, the transmission of DVB-C channels over an external modulated optical link using a Mach-Zehnder modulator (MZM). We will also observe the consequences of biasing the MZM near its transmission minimum point, which allows higher carrier to noise ratio at the transmitter, but increases second-order distortion at the receiver.

Electromagnetic characterization of millimetre-scale replicas of the gyroid photonic crystal found in the butterfly Parides sesostris

We have used three-dimensional stereolithography to synthetically replicate the gyroid photonic crystal (PC) structure that occurs naturally in the butterfly Parides sesostris . We have experimentally characterized the transmission response of this structure in the microwave regime at two azimuthal angles ( ϕ ) over a comprehensive range of polar angles ( θ ). We have modelled its electromagnetic response using the finite-element method (FEM) and found excellent agreement with experimental data. Both theory and experiment show a single relatively broad transmission minimum at normal incidence ( θ = 0°) that comprises several narrow band resonances which separate into clearly identifiable stop-bands at higher polar angles. We have identified the specific effective geometric planes within the crystal, and their associated periodicities that give rise to each of these stop-bands. Through extensive theoretical FEM modelling of the gyroid PC structure, using varying filling fractions of material and air, we have shown that a gyroid PC with material volume fraction of 40 per cent is appropriate for optimizing the reflected bandwidth at normal incidence (for a refractive index contrast of 1.56). This is the same gyroid PC material volume fraction used by the butterfly P. sesostris itself to produce its green structurally coloured appearance. This infers further optimization of this biological PC beyond that of its lattice constant alone.

Transmission Characterization of Drilled Alternating-Layer Three-Dimensional Photonic Crystals

We propose a new three-dimensional photonic crystal structure or drilled alternating-layer photonic crystal (DALPC), which can be fabricated by a combination of the deposition of alternating layers of dielectric films and one-time dry etching. Our band calculation predicts that the DALPC has a photonic band gap (PBG) in all directions. We fabricated a Si/SiO2DALPC by electron beam lithography, bias sputtering, and fluoride-gas electron cyclotron resonance etching. We measured the light transmission of the DALPC sample in both the in-plane and vertical directions. We observed a transmission minimum around the 1.4-μm-wavelength for all measured directions and TE/TM polarizations, which demonstrated a potential of the DALPC as a three-dimensional PBG material.

Transmission Characterization of Drilled Alternating-Layer Three-Dimensional Photonic Crystals

We propose a new three-dimensional photonic crystal structure or drilled alternating-layer photonic crystal (DALPC), which can be fabricated by a combination of the deposition of alternating layers of dielectric films and one-time dry etching. Our band calculation predicts that the DALPC has a photonic band gap (PBG) in all directions. We fabricated a Si/SiO2 DALPC by electron beam lithography, bias sputtering, and fluoride-gas electron cyclotron resonance etching. We measured the light transmission of the DALPC sample in both the in-plane and vertical directions. We observed a transmission minimum around the 1.4-µm-wavelength for all measured directions and TE/TM polarizations, which demonstrated a potential of the DALPC as a three-dimensional PBG material.