Ultra-high resolution filter and optical field modulator based on a surface plasmon polariton

Abstract

A new filter structure and optical field modulator with ultra-high resolution based on plasmonic nano-cavity resonators is proposed and numerically investigated. The structure consists of a square nano-cavity resonator connected with several waveguides. All waveguides and cavity are etched on a silver film whose size is 1.1×0.75 μm. Compared with traditional filters, the FWHM (full width at half-maximum) of this structure's spectrum curve can be less than 7 nm; namely, the resolution has been greatly improved. The structure also presents the feature of an optical field modulator when both inputs are working simultaneously, and it provides a promising way to design and manufacture future optical logical device.

Plasmonic circuits for manipulating optical information

“…Examples of photonic devices created for plasmons are shown in Figure 4 and include "Y" junctions for combining or separating plasmons [68][69][70][71][72], "X" junctions [70], proximity couplers [73], directional couplers [74] [73, [75][76][77][78], Bragg grating filters [69,79], add-drop filters [80], and ring resonators [69,79,81] that transmit or reflect plasmon waves depending on frequency and switching using phase shifts [82]. A novel plasmon filter was created using two wires of different materials joined together that provided a large electric permittivity mismatch resulting in unidirectional propagation [83].…”

High sensitivity microsensor assisted by Fano resonance in InSb based terahertz plasmonic waveguide

“…Surface plasmon polaritons (SPPs) have shown the considerable potential to control light at the subwavelength scale due to their ability of overcoming the diffraction limit [1]. Recently, huge kinds of highly integrated optical devices have been investigated or demonstrated assisted by plasmonic nanostructures, such as perfect absorbers [2,3], filters [4][5][6], all-optical switches [7][8][9], and nanofocusing structures [10][11][12]. Among these devices, plasmonic sensors for refractive index sensing have been explored by means of the classical analogue of electromagnetically induced transparency (EIT) [13][14][15] or perfect absorption resonance [16][17][18].…”

Plasmonic Refractive Index Sensor with High Figure of Merit Based on Concentric-Rings Resonator

“…Surface plasmon polaritons (SPPs) are electromagnetic fields propagating along the interface of metal-insulator, and have been widely discussed for several decades due to the ability to modulate light in nanoscale as well as break the diffraction limit [1]. Recently, many kinds of plasmonic devices have been investigated such as filters [2], absorbers [3], splitters [4] and sensors [5]. Among these, plasmonic sensors have drawn more attention, because compared with traditional optical sensors such as fiber sensors and silicon-based sensors, plasmonic sensors have much smaller size with comparable sensing performance, which means they are more suitable for integrating [6].…”