Wavelength Tunable Surface Plasmon Resonance-Enhanced Optical Transmission Through a Chirped Diffraction Grating

Abstract

We report the construction and testing of a chirped diffraction grating, which serves as a substrate for surface plasmon-enhanced optical transmission. This grating possesses a spatial variation in both pitch and amplitude along its surface. It was created by plasma oxidation of a curved poly(dimethoxysilane) sheet, which resulted in nonuniform buckling along the polymer surface. A goldcoated replica of this surface elicited an optical response that consisted of a series of narrow, enhanced transmission peaks spread over the visible spectrum. The location and magnitude of these transmission peaks varied along the surface of the grating and coincided with conditions where surface plasmons were excited in the gold film via coupling to one or more of the grating's diffracted orders. A series of measurements were carried out using optical diffraction, atomic force microscopy, and normal incidence optical transmission to compare the grating topology to the corresponding optical response. In addition, the impact of a thin dielectric coating on the transmission response was determined by depositing a thin silicon oxide film over the grating surface. After coating, wavelength shifts were observed in the transmission peaks, with the magnitude of the shifts being a function of the film thickness, the local grating structure, and the diffracted order associated with each peak. These results illustrate the ability of this surface to serve as an information-rich optical sensor whose properties can be tuned by control of the local grating topology.

Universal sensitivity of propagating surface plasmon resonance in nanostructure arrays

“…For example, nanohole arrays in metal films with various configurations in terms of film thickness, hole size, periodicity and pattern exhibited distinct optical response and sensitivities [7][8][9][10]. Sensitivity expressions for regular and chirped diffraction gratings were derived with wavelength shifts being a function of the local structures and diffraction orders [11,12]. However, most of current results were associated with the single arrangement of individual exciting mechanism, thereby hindering the direct comparisons across various configurations.…”

Microfabrication and Applications of Opto-Microfluidic Sensors

“…SPP cannot be directly excited by photons due to momentum mismatch. Special arrangements, such as Otto configuration [76], Kretschmann configuration [77], or a diffraction grating [78], are well-known techniques to couple photons into SPP in order to match the wave vectors of the photon and the surface plasmon, as illustrated in Figure 9. The Kretschmann configuration is the most common approach, in which the thickness of the metal layer is usually a few tens of nanometers to ensure the evanescent wave to travel through the metal and couple to a surface plasmon mode, which is shown in Figure 9(d).…”

In Situ Study of Electropolymerized Poly(3-aminobenzoic acid) Thin Film on BD-R and DVD-R Grating Substrates by Electrochemical-Transmission Surface Plasmon Resonance Spectroscopy

“…Moreover, the commercial available recordable compact disc (CD-R), recordable digital versatile disc (DVD-R), and recordable Blu-ray disc (BD-R) can also be served as the inexpensive transparent grating substrates in this technique. The advantages of gratings, which make them a highly flexible and tunable platform for sensor applications, are (1) inherently information-rich substrates whose surface plasmon appears in various diffracted orders and (2) changing of amplitude, shape, or pitch of the grating profiles affecting wavelength and shape of plasmon resonance [8][9][10].…”