Optical transmission of corrugated metal films on a two-dimensional hetero-colloidal crystal

Abstract

The near infrared transmission of corrugated metal films deposited on hetero-colloidal crystals is investigated. The transmission response of the quasi-three-dimensional (quasi-3D) metal film is modified by controlling the nominal thickness of a dielectric layer pre-deposited on the top surface of the colloidal crystal to form a new hetero-colloidal crystal. An extraordinary optical transmission (EOT) phenomenon could be presented in such metallodielectric (MD) architectures. We have found that the main transmission peak is suppressed as the thickness of the intercalated dielectric layer is increased. We propose that the observed EOT is a result of constructive interference between a localized sphere-like plasmon mode and an index-guided eigen mode mainly confined in the colloidal crystal, which is confirmed by our numerical simulations. Based on the MD microstructures, a distinct plasmon sensitivity response difference is achieved, which indicates potential applications for biochemical sensing.

Making a Conducting Metal with Optical Transparency via Coupled Plasmonic-Photonic Nanostructures

“…Two main evolution processes could be observed: one is the continuously narrowing transparent bandwidth with the decreasing refractive index of the dielectric layer and the other is the reduced transmittance intensity for the transparency window. For instance, the T max for the proposed scheme with a dielectric layer of n=1.5 is only 79.5 %, which is much smaller than that of the case with a larger n. This is the result of the weak optical field coupling and confinement by the low refractive index dielectric layer [17].…”

“…However, the natural light opaque response for the metal film structure is a critical obstacle before the forward for numerous applications [12][13][14]. A typical approach to achieve high light transmittance is to introduce holes or slits in the metal film structure, which could provide efficient optical field coupling via the plasmon resonances and produce enhanced optical transmission [15][16][17][18][19][20][21][22]. For instance, in the hedgehog hole arrays and double periodic hole arrays, enhanced transmission has been demonstrated by utilizing the coupling between localized and propagating plasmonic modes [23][24][25][26][27][28].…”

Improving Plasmon Sensing Performance by Exploiting the Spatially Confined Field

“…That is, an enhancement factor of 57 is achieved for the FOM*of the sensor compared with the sensor without etching. These sensing performance factors are also much larger than the conventional plasmonic sensing systems including the nanorods [27], nanoholes [36,37], and plasmonic-photonic crystalbased absorbers [22]. The PA-based sensor with ultra-high FOM* can present a potential for the application of ultrasensitive biosensing and particularly for the detection of weak signal in the complex surrounding [22,26,28].…”

Refractometric sensing of silicon layer coupled plasmonic–colloidal crystals

“…Many efforts have been made by using the polarized surface electron oscillations [4][5][6] in the well designed plasmonic structures [7][8][9][10][11][12][13]. Currently, great attention on the sensing has been attracted for the plasmonic M-CCs [14][15][16] thanks to their simple and low-cost fabrication features. Nevertheless, due to the highly confined optical cavity-like mode existing in the CC, relatively low sensitivity is obtained [16], which inevitably leads to strong limitations for further applications.…”