Detuned surface plasmon resonance scattering of gold nanorods for continuous wave multilayered optical recording and readout

Adam B Taylor,Jooho Kim,James W M Chon

doi:10.1364/oe.20.005069

Abstract

In a multilayered structure of absorptive optical recording media, continuous-wave laser operation is highly disadvantageous due to heavy beam extinction. For a gold nanorod based recording medium, the narrow surface plasmon resonance (SPR) profile of gold nanorods enables the variation of extinction through mulilayers by a simple detuning of the readout wavelength from the SPR peak. The level of signal extinction through the layers can then be greatly reduced, resulting more efficient readout at deeper layers. The scattering signal strength may be decreased at the detuned wavelength, but balancing these two factors results an optimal scattering peak wavelength that is specific to each layer. In this paper, we propose to use detuned SPR scattering from gold nanorods as a new mechanism for continuous-wave readout scheme on gold nanorod based multilayered optical storage. Using this detuned scattering method, readout using continuous-wave laser is demonstrated on a 16 layer optical recording medium doped with heavily distributed, randomly oriented gold nanorods. Compared to SPR on-resonant readout, this method reduced the required readout power more than one order of magnitude, with only 60 nm detuning from SPR peak. The proposed method will be highly beneficial to multilayered optical storage applications as well as applications using a continuous medium doped heavily with plasmonic nanoparticles.

Highlights

Interests in plasmonic nanoparticle based optical recording and patterning is gaining momentum [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]
We have proposed the detuned continuous wave recording and readout on gold nanorod based multilayered optical storage, and demonstrated the 16 layer readout with more than one order of magnitude reduction in laser power by detuning only 60 nm from surface plasmon resonance (SPR) peak
This work will be obviously highly beneficial to future high-density optical storage applications based on gold nanorods, where complicated pulsed laser operation can be replaced with cost and space effective continous wave lasers

Summary

Introduction

Interests in plasmonic nanoparticle based optical recording and patterning is gaining momentum [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18]. Scattering peak is broadened for all layers as expected, which result a) increase in amount of detuning from SPR peak (~100 nm of peak evolution illustrated in Fig. 2(F)), and b) the readout signal power enhancement at off-resonant wavelengths at deeper layers being diminished (enhancement only to 2.4 times at 16th layer, compared to single size, aligned case of 60 times). This illustrates that the readout wavelength needs to be carefully selected with detuning information gained from Fig. 2(F), Fig. 3(C), and Fig. 3(E)

Experimental

Findings

Conclusions