No abstract

Highly efficient, active and compact, unidirectional surface plasmon (SP) propagator composed of double subwavelength slits; filled with organic electro-optic (EO) material is proposed and investigated. By selecting appropriate structure parameters, obtained by solving phase relations between slits, the relative phase of SP generated at the slit exit aperture can be tailored. Simulation results show under normal illumination and external voltage of 8.7 V, SP launching efficiency of 55% and unidirectional SP extinction ratio about 47dB at wavelength of 632.8 nm is achieved. The power consumption of the structure is on the order of 9 fJ/bit which meet the power consumption limitation for optical devices. Moreover, the structure is very compact with effective total length of 1.2 µm and thickness of 0.6 µm.

No abstract

Extraordinary gain-assisted transmission in telecommunication regimes through circular nanohole arrays drilled on a metallic film is investigated theoretically. Silicon-compatible Er-Yb silicate, which has a photoluminescence peak in the telecommunication regime, was selected for optical amplification purposes. Geometrical parameters were optimized analytically in order to present transmission resonances at telecommunication regions. The required gain value for lossless propagation was determined by considering the surface-plasmon dispersion relation. Simulation results show that the predicted gain for lossless propagation cannot completely compensate the loss. By increasing gain value, absorption becomes zero and transmission approaches unit through a laser with a pumping power of 372 mW at 1480 nm.

We proposed and demonstrated a high-efficiency active absorber based on surface plasmon polaritons and Fabry-Perot cavity operating at telecommunication regime. The absorber comprised a resonance-cavity grating sandwiched between a metal and vanadium dioxide (VO 2 ), a phase-change material (PCM) widely used in optical devices. As a PCM, VO 2 is characterized by a large difference in the refractive index between the insulator and metallic phases initiated by various stimuli, such as heat, voltage, and current, thereby enabling the tailoring of optical properties in different systems. Herein, heating caused VO 2 to undergo a transition from insulator to metallic phase, resulting in changes in its optical properties. For transverse magnetic polarization at resonance wavelength, the cavities beneath the VO 2 confined the impinging light when VO 2 was in insulator phase. Our simulation results revealed that the confinement enhanced the absorption up to 99%; conversely, when the system was heated beyond the phase-transition temperature of VO 2 (68 °C), the absorption intensity decreased from 99% to 30%. For transverse electric polarization, a similar behavior was observed but the absorption intensity was about 50% at telecommunication band. These findings indicated that the proposed absorber was active, intensity tunable and highly responsive and may have applications in sensors and imaging.