Chia-Yi Chen

Extraordinary transmission through a silver film perforated with cross shaped hole arrays in a square lattice

In this work, the transmission through cross shaped hole with different sizes but the same lattice constant was measured with the polarized light to investigate the variation of localized charge oscillation around the hole. The comparison between the transmission intensities through the similarly arranged periodic hole array with different hole shapes, i.e., cross, square, and rectangular, were also measured. The cross shaped hole gives rise to a larger transmission of light than those perforated with square or rectangular hole.

Reflection and emission properties of an infrared emitter.

The reflection and emission properties of an infrared emitter, which is a plasmonic multilayer structure consisting of a relief metallic grating, a waveguide layer, and a metallic substrate are investigated both experimentally and theoretically. A localized surface plasmon polariton (SPP) mode which is angular-independent in almost the full range of incident angles is observed. The thermal emission of this structure is also measured. It is found that the emission peak coincides with the angular-independent localized SPP mode. In addition, the emission spectrum of the plasmonic emitter can be predicted by investigating the reflectance spectrum.

Wavelength selective quantum dot infrared photodetector with periodic metal hole arrays

In this letter, the effect of extraordinary transmission of periodic metal hole arrays is directly integrated into the quantum dot infrared photodetector with broadband response. It is found that the detector response is strongly modulated by the extraordinary transmission from the excitation of surface plasmon.

Effect of Wood’s anomalies on the profile of extraordinary transmission spectra through metal periodic arrays of rectangular subwavelength holes with different aspect ratio

The extraordinary transmission through silver film perforated with rectangular hole array with different aspect ratio was investigated. It was found that when the aspect ratio exceeded 7, the propagating surface plasmon polaritons (SPPs) transformed to localized resonance mode. The role of the Woods anomaly on the shape of the transmission spectrum is investigated. By designing the rectangular hole arrays in a rectangular lattice, the Woods anomaly can be shifted far apart from the transmission peak, the real localized resonance peak wavelength was identified and fitted well with the theoretical calculation using a simplified transmission-line model.

Localized surface plasmon polaritons in Ag∕SiO2∕Ag plasmonic thermal emitter

The reflection dispersion relation and emission spectra of Ag∕SiO2∕Ag trilayer plasmonic thermal emitters with different lattice constant and Ag line width were investigated. The top Ag film is perforated with parallel line-shape hole array. The induced Ag∕SiO2 surface plasmons at both top and bottom Ag∕SiO2 interface are found coupled together. The coupling effect results in the localized surface plasmon polaritons confined at the top Ag∕SiO2 interface which exhibit the Fabry–Perot resonance. The thermal emission peak position coincides with the reflection minimum in the dispersion relation and shifts to long wavelength as the Ag line width increases, which proves that the emission is due to the excitation of localized surface plasmon polaritons. Moreover, the emitted light is polarized perpendicular to the parallel metal lines.

Coupling of surface plasmons between two silver films in a Ag/SiO2/Ag plasmonic thermal emitter with grating structure

The reflection and emission spectra of Ag/SiO2/Ag trilayer plasmonic thermal emitters with different SiO2 thicknesses are investigated. The top Ag film is perforated with periodic slits. It is found that the coupling of surface plasmons at the top and bottom Ag/SiO2 interface results in the redshift in thermal emission peaks. In this Ag/SiO2/Ag plasmonic thermal emitter, the electromagnetic field exhibits either Fabry–Perot resonance or propagating surface plasmons depending on the thickness of SiO2 layer. By varying the thickness of SiO2 layer, transition from localized to grating-coupled propagating surface plasmon modes is observed.

Coupling of surface plasmons between two silver films in a plasmonic thermal emitter

The emission spectra of Ag∕SiO2∕Ag trilayer plasmonic thermal emitters with various SiO2 thicknesses were investigated. By analyzing the relationship between emission peaks and thicknesses of SiO2, the coupling of surface plasmons between two silver films in a plasmonic thermal emitter is demonstrated and the coupling length is determined as well. Furthermore, the dispersion relation of plasmonic thermal emitter is detected by measuring the reflection spectra with various incident angles. This confirms that the main mechanism involved in the emission of a plasmonic thermal emitter is due to the excitation of surface plasmons.

Strong photoluminescence emission from resonant Fibonacci quantum wells

Strong photoluminescence (PL) emission from a resonant Fibonacci quantum well (FQW) is demonstrated. The maximum PL intensity in the FQW is significantly stronger than that in a periodic QW under the Bragg or anti-Bragg conditions. Moreover, the peaks of the squared electric field in the FQW are located very near each of the QWs. The optimal PL spectrum in the FQW has an asymmetrical form rather than the symmetrical one in the periodic case. The maximum PL intensity and the corresponding thickness filling factor in the FQW become greater with increasing generation order.

Enhancement of Thermal Radiation in Plasmonic Thermal Emitter by Surface Plasmon Resonance

The emission spectra of Ag/Si02/Ag tri-layer plasmonic thermal emitters were investigated. It is demonstrated that the top silver film perforated with periodic hole arrays plays a role to amplify the thermal emission in the emitter at a specific wavelength determined by the surface plasmon. Obviously the amplification of the thermal radiation is independent of lattices. The amplification of thermal radiation at specific wavelength was induced by the strong surface plasmon resonance. In addition, it provides a useful tool to be applied in the area of gas sensing and probing the response of cells and plants to the infrared radiation. Furthermore, the emittance spectra with decreasing sized holes were measured and the peak position red shift was observed, the result was attributed to the variation of effective refractive index.

Coupling between surface plasmons via thermal emission of a dielectric layer sandwiched between two metal periodic layers

Metal/SiO2/metal trilayer thermally generated infrared emitters with different top and bottom periodic metal arrangements were fabricated and their emission spectra were measured. The coupling mechanisms of surface plasmon polaritons at top and bottom periodic metal structures were characterized. It is found that the top surface plasmon converted to light radiation directly, whereas the bottom surface plasmon can radiate out when its emission peak position matches that of the top surface plasmon. This opens the way to fabricate the high temperature operated, narrow bandwidth, and multiwavelength infrared light source.