Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons

Summary

This protocol describes the instrumentation for determining the excitation and coupling rates between light emitters and Bloch-like surface plasmon polaritons arising from periodic arrays.

Abstract

We have developed a unique method to measure the excitation and coupling rates between the light emitters and surface plasmon polaritons (SPPs) arising from metallic periodic arrays without involving time-resolved techniques. We have formulated the rates by quantities that can be measured by simple optical measurements. The instrumentation based on angle- and polarization-resolved reflectivity and photoluminescence spectroscopy will be described in detail here. Our approach is intriguing due to its simplicity, which requires routine optics and several mechanical stages, and thus is highly affordable to most of the research laboratories.

Introduction

Surface plasmon mediated fluorescence (SPMF) has received considerable attention recently^1,2,3,4,5,6. When light emitters are placed in close proximity to a plasmonic system, energy can be transferred between the emitters and surface plasmon polaritons (SPPs). In general, the strong plasmonic fields can strongly enhance the excitation of the emitters². At the same time, the emission rate is also increased because of the large density-of-states creat....

Protocol

1. Setup of Interference Lithography

NOTE: Interference lithography is used to fabricate the periodic arrays¹². The schematic setup, as is shown in Figure 1, is built up as follows:

1. Focus the 325 nm laser from a HeCd multimode laser to a 13X UV objective lens and pass it through a 50 μm pinhole based spatial filter for mode cleaning.
2. Place two 2.5 cm diameter irises 30 cm apart to further filter the central region of the diverging light. After the second iris, the beam diameter equals 2.5 cm and increases very slowly with distance, which is < 3 cm at 1 m distance fr....

Results

An example of an Au periodic array is given in the inset of Figure 4a⁸. The plane view SEM image shows that the sample is a 2D square lattice circular hole array with a period of 510 nm, a hole depth of 280 nm, and a hole diameter of 140 nm. The p-polarized reflectivity mapping taken along the Γ-X direction is shown in Figure 4a. The dash line is calculated by the phase matching equation Eq. (1) indicating.......

Discussion

In this protocol, there are several critical steps. First, mechanical stability is crucial in sample preparation. The standing wave generated by Lloyd's setup is sensitive to the phase difference between two illumination beams. Therefore, any vibration during the exposure time will degrade the uniformity and edge sharpness of the nanohole. It is highly recommended to operate in a vibration-free environment, e.g., an optical table with vibration isolation supports. In addition, high power laser is also desired to.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
SU-8	MicroChem	SU-8 2000.5
Adhesion solution	MicroChem	Omnicoat
SU-8 Thinner (Gamma-Butyrolactone)	MicroChem	SU-8 2000 Thinner
SU-8 Developer	MicroChem	SU-8 Developer
Spin Coater	Chemat Technology	KW-4A
HeCd laser	KIMMON KOHA CO., LTd	IK3552R-G
Shutter	Thorlabs	SH05
Objective for sample preparation	Newport	U-13X
Pinhole	Newport	PNH-50
Iris	Newport	M-DI47.50
Prism	Thorlabs	PS611
Rotation stage for sample preparation	Newport	481-A
Supttering Deposition System	Homemade
Rotation Stage 1	Newport	URM80ACC
Rotation Stage 2	Newport	RV120PP
Rotation Stage 3	Newport	SR50PP
Detection arm	Homemade
Quartz lamp	Newport	66884
Fiber Bundle	Newport	77578
Objective for measurement	Newport	M-5X & M-60X
Polarizer & Analyzer	Thorlabs	GT15
Multimode Fiber	Thorlabs	BFL105LS02
Spectrometer	Newport	MS260i
CCD	Andor	DV420-OE
514nm Argon Ion Laser	Spectra-Physics	177-G01
633nm HeNe Laser	Newport	R-32413
CdSeTe quantum dot	Thermo Fisher Scientific	q21061mp
Polyvinyl alcohol polymer (PVA)	SIGMA-ALDRICH	363073
Control program	National Instruments	LabVIEW