EMISSION ENHANCEMENT CHARACTERISTICS OF OXAZINE IN PMMA MATRIX INFLUENCED BY SURFACE PLASMON...

April 18, 2012 18:55 WSPC/S0218-8635 145-JNOPM 1250013

Journal of Nonlinear Optical Physics & MaterialsVol. 21, No. 1 (2012) 1250013 (13 pages)c© World Scientific Publishing CompanyDOI: 10.1142/S0218863512500130

EMISSION ENHANCEMENT CHARACTERISTICSOF OXAZINE IN PMMA MATRIX INFLUENCEDBY SURFACE PLASMON POLARITON INDUCED

ON SINUSOIDAL SILVER GRATING

WILZUARD YONAN WISMANTO∗, RAHMAT HIDAYAT†, MAY ON TJIA†,YASUMASA FUJIWARA∗, KOJI MURATA∗, YASUHIRO OGAWA∗,

HIROYUKI YOSHIDA∗, AKIHIKO FUJII∗ and MASANORI OZAKI∗,‡

∗Graduate School of Engineering, Osaka University,2-1 Yamada-oka, Suita-shi, Osaka-fu, 565-0871, Japan

†Physics of Magnetism and Photonics,Faculty of Mathematics and Natural Sciences,Institut Teknologi Bandung, Jl. Ganesha 10,

Bandung 40132, Indonesia‡[email protected]

Received 1 December 2011Published 23 April 2012

We present the result of an experimental study on the photoluminescence of a thin layerof oxazine molecules doped into the poly(methyl methacrylate) (PMMA) matrix whichis coated on top of sinusoidal silver grating. The surface plasmon polaritons that occuron the metallic grating surface were excited by a He-Ne laser of 633 nm wavelength.The effect of the grating was investigated by angle-resolved reflection and emission spec-troscopy performed on the thin film samples with and without the grating. Incidentlight of both s- and p-polarizations were considered in this experiment and the mea-surement was performed in the reflection and the photoluminescence modes as well. Theresults exhibit remarkable resonant effect of photoluminescence enhancement over thoseobserved from the sample with planar silver coating for both incident light polarizations.The much larger enhancement factor of ∼50.0 found for the case of p-polarized lightcan be attributed to the combined contributions of surface plasmon polariton enhancedabsorption of excitation light and the resonant coupling between the SPP and the flu-orophore, while only the latter was operating in the case of s-polarized incident light

which showed a smaller enhancement factor of 6.0.

Keywords: Surface plasmon polariton; photoluminescence enhancement; oxazine; sinu-soidal grating.

1. Introduction

The development of organic semiconductor-based optoelectronic devices hasattracted increasing research interest as evidenced by the growing number of pub-lished reports in this field. This rising trend is mainly due to the less demand-ing technology for the material synthesis and the associated device fabrication

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http://dx.doi.org/10.1142/S0218863512500130


W. Y. Wismanto et al.

and hence, the corresponding low production cost. In addition, the rich flexibil-ity of organic molecular architecture further offers the opportunity for tailoringand improving the material functionalities or even exploring possibilities for novelapplications. A large variety of organic semiconductor-based devices have been suc-cessfully developed such as the organic light-emitting diodes (OLED)1−3 organicphotovoltaic cells,4−6 organic field-effect transistors7−9 and bio-sensors.10−12 Someof these devices have even successfully found their ways into the commercial market.

Meanwhile, it is well recognized that there are rooms for further improvement ofthe product’s cost-effectiveness and this has become a highly challenging researcharea which is marked by effort of pursuing various means to increase the device per-formances. For instance, in the case of OLED, further enhancing the luminescenceefficiency and improving the homogeneity of its emitted spectral profile remainthe major issues to be addressed for advancing the device performances. One ofthe alternative approaches adopted recently to meet the challenges is the utiliza-tion of induced surface plasmon polariton (SPP) and its interaction with the fluo-rophore, leading to the fluorescence enhancement arising from the expected resonanteffect.

A number of reports have been published as the result of researches performedin this direction.13−15 It is well known that on flat metal coated luminescencematerials, the SPP can only be produced by the p-polarized electromagnetic waveand only rather broad and relatively moderate increase in the emission intensity wasobserved without exhibiting perceptible resonant enhancement effect.16,17 However,the much sought-after resonant enhancement effect was successfully demonstratedwhen sinusoidal corrugated metallic surface was employed with optical irradiationof s- or p-polarized wave18,19 where the effect will occur on light polarization thatis parallel to the grating vector. The spectral structure that consists of a series ofresonant peaks was attributed to the periodic structure of the metallic surface withthe peak positions nicely correlated to the Surface Plasmon Resonance (SPR) wavenumbers observed in the reflection mode, in good agreement with the theoreticaldescription involving the umklaap mechanism.20

In this paper, we report the result of our experimental study on the photolu-minescence (PL) characteristics of oxazine molecules in PMMA matrix depositedon top of the sinusoidal silver grating. This fluorophore is known to exhibit rela-tively long-wavelength PL intensity21 and is therefore suitable for readily revealingits enhancement effect since their emission won’t be affected by background signalfrom the host matrix. The result of the present experiment does show the observa-tion of the SPP enhancement effect induced by the irradiation of p- (TM) as well ass- (TE) polarized waves of a pump source on the silver grating surface. The resultantremarkable PL resonant enhancement factors over the PL spectra detected usingflat silver layer are measured and compared for incident light of the two differentpolarizations. Further discussion is presented on the observed PL characteristicsand the difference related to the different polarizations of the incident waves alongwith elucidation of the underlying physical processes.

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Emission Enhancement Characteristics of Oxazine in PMMA Matrix Influenced by SPP

2. Experimental

2.1. Sample preparation

For the preparation of the sample, a 1 mm thick glass substrate was cut into15 mm × 15mm size and cleaned by a standard cleaning procedure. A photoresistsolution, OFPR-800 from Tokyo Ohka, was spun onto the pre-cleaned substrates at3000 rpm, followed by baking the substrates on a hot plate at 100◦C for 90 secondsto evaporate the residual solvent, followed by cooling it down to room temperature.The film deposited on the glass substrate is about 1.4µm thick, as estimated fromthe atomic force microscopy (AFM) measurement. A one dimensional grating wasimprinted on 12.5π mm2 area of the photoresist layer by means of the Lloyd-mirrorinterference lithography using the third harmonic output (355nm in wavelength)from a Q-switched Nd:YAG laser. The process was continued with the post-exposurebaking and developing processes. A thin silver layer of ∼50nm was depositedthereafter on the grating surface by electron beam evaporation. Finally, a mixturesolution of 1wt% oxazine 750 perchlorate (Ox) (from Exciton) and poly(methylmethacrylate) (PMMA) (from Sigma Aldrich) was spun on the silver grating sur-face at a rotation speed of 3000 rpm for 30 seconds. This dye doped polymer filmhas a thickness of about 44 nm, as determined by AFM measurement. This thick-ness ensures that no light guiding modes will be supported within the entire gratinglayer.

2.2. SPR and photoluminescence spectra measurements

In this experiment, the performance characteristics of the grating samples wereinvestigated by SPR (reflection) and PL spectra measurements. The experimentalsetup used is basically the same as general PL spectra measurement, shown inFig. 1. The sample was placed on a rotating stage in the x-y plane for angle-dependent measurements. The incident light beam was aligned and focused on thex-z plane, by means of a set of lenses and a pinhole, onto the sample surface of

Fig. 1. Schematic illustration of the PL measurement for s- and p-polarization of the propagatinglight with respect to grating orientation.

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circular illuminated area with 1mm diameter. The reflection and PL spectra of thesample were obtained by a multichannel spectrophotometer (PMA-11, HamamatsuPhotonics). The irradiating incident light employed was either s- or p-polarized bya polarizer. A tungsten lamp (MHF-100L, MORITEX) was used in the reflectionmeasurements while a 632.8 nm He-Ne laser (Showa Optronics Co.) was employedin the PL measurements as the light sources. In the PL measurements, a 670nmcut filter (R67) was placed in front of the light guiding coupler of the multichannelspectrophotometer in order to block off the incident laser beam. The measurementswere performed by varying either the incident angle θi or the detection angle θd.Using an additional polarizer in front of the cut-filter, the relative contributions ofdifferent (s- and p-) polarization components in the emitted light were also measuredfor incident light of either polarization.

3. Results and Discussion

3.1. SPR and PL enhancement characteristics

Figure 2 shows the normalized absorption and PL spectra of oxazine in PMMAmatrix, indicating strong absorption in the wavelength range of 600–700nm andthe corresponding PL emission in the range of 650–850nm. The He-Ne laser istherefore suitable to serve as the excitation light source for the detection of thatspectra and the following studies of the SPP effects on the PL emission. It is seenthat the figure displays typical mirror-symmetric spectral profile of the two spectra.

The following measurement was conducted on the grating sample preparedas described in Subsec. 2.1. The AFM image of the fabricated grating is shownin Fig. 3, which indicates the formation of sinusoidal corrugated pattern with

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orm

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Absorption Emission

oxazine PMMA

+

Fig. 2. Absorption and emission spectra of oxazine in PMMA matrix.

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Fig. 3. AFM image of the resultant grating structure.

∼400nm periodicity and about ∼100nm corrugation depth. These structuralparameters were obtained as a result of the appropriate choice of the pulsedlaser energy of 150mW, the number of laser pulse (1) and the Lloyd-mirror angleof 26.3◦.

Figure 4(a) shows the results of SPR spectra measured from the sample ofoxazine doped polymer layer deposited on corrugated silver surface where the grat-ing vector is parallel to the x-axis of Fig. 1. The spectra were measured with boththe light source at an angle θi = 7◦ and the detector fixed at an angle of reflection.The sample was irradiated separately by either p-polarized or s-polarized incident

(a) (b)

Fig. 4. (a) SPR spectra of oxazine doped polymer layer on silver grating measured with thes- and p-polarized incident light at fixed incident angle. (b) The corresponding dispersion curvededuced from SPR spectra measured at various incident angles.

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light from the tungsten lamp. It is seen that the figure exhibits a typical reflectionspectrum arising from the SPR effect for the p-polarized incident light while no signof this effect is observable for the s-polarized incident light, confirming the alreadywell known observation in the case of flat metallic surface. The result of two SPRdips detected for p-polarized incident light is typical of grating coupled SPR whichis described by the resonance condition given by:

k(m)SP = kix + mGn, (1)

or in terms of the related magnitude,∣∣k(m)

SP

∣∣ =

ω

cn sin θi + m

2π

Λ, (2)

where n is the refractive index of the dielectric medium and m = 0,±1,±2, . . . . Thetwo dips appearing in the detected spectrum are then related with the m = ±1 ofthe SPR wavenumber modes. As inferred from Eq. (2), increasing the incidentangle leads to more widely spaced dip positions with one dip shifted to the longerwavelength while the other shifted to the shorter wavelength. At normal incidentangle, kx = 0, only one dip or even no dip may appear, depending on the valueof grating period (Λ), in good agreement with the previous observation.22−24 Ondeduction of the photon energies corresponding to each dip from the SPR spectrameasured at various incident angles, one arrived at the dispersion relation plottedin Fig. 4(b). Based on the extrapolation of this plot, one is led to conclude that nodiscernable band gap is expected to appear at kx = 0, as predicted by previouslyreported observation25 and in contrast to the result reported for the case withbiharmonic silver grating.26

Figure 5 shows the PL spectra obtained from the same samples measured atvarious detection angles (θd) with fixed incident angle (θi = 20◦). It should be noted

Fig. 5. (Color online) PL spectra measured from oxazine doped polymer on silver grating atvarious detection angles but at the same incident angle of 20◦.

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that since the sample was excited by p-polarized monochromatic light source froma 632.8 nm He-Ne laser, the detected spectrum lying within the emission spectralrange as shown in Fig. 2 is clearly the result related to the oxazine emission insteadof the reflected light. The PL spectrum contains a series of emission lines withnarrow bandwidth detected at different angles with a fixed incident angle of θi =20◦, mimicking the inverted SPR spectra presented in Fig. 4(a). It is also observedthat the angle dependent intensity variation appears to follow the emission lineshape of oxazine in PMMA matrix as displayed in Fig. 2. This indicates the effectof coupling between the PL emission and the surface plasmon polariton inducedalong the metal grating structure, resulting in the PL featuring the typical SPRmode characterized by the same angle-dependent resonance condition governed byEq. (1) with the kix term replaced for this case by the emitted light wavenumberalong the grating (kex). This observation will be corroborated by experimental resultdescribed in the following along with further elaboration of the PL characteristicsand its possible underlying physical process.

3.2. Polarization dependent PL characteristics

Despite the absence of SPR signal in the reflection spectrum observed with s-polarized incident light, we move on to our major aim of investigating the possibleresonant PL enhancement for this case. As implied by the different SPR responsementioned above, it is only natural to expect a different feature of the PL spectraobserved with different incident wave polarizations.

For better understanding of the physical mechanism responsible for the observedphenomena, it is useful to compare the characteristics of those PL spectra inducedseparately by the s- and p-polarized incident light. Presented in Fig. 6 are thePL spectra measured at various incident angles with a fixed detection angle ofθd = 0 for (a) s-polarized and (b) p-polarized incident light. In each case, the figureis provided with a reference spectrum obtained from the sample coated with flatsilver layer with the measurement condition described by the inset of Fig. 6(a). Itis important to note that all PL spectra presented in both Figs. 6(a) and 6(b) havetheir maximum intensities appearing at about 675 nm, practically coinciding withthe emission peak of oxazine in PMMA matrix. It is also noted that the emissionprofiles in both cases closely resemble the emission profile given in the inset ofFig. 1. More importantly, one readily observes that only the spectral intensity inthe case of p-polarized incident light exhibits the θi-dependent variation. This is aclear indication of the effective generation of SPP by the p-polarized incident lightwhich in turn induces the SPP enhanced absorption of the 633nm pump light by thefluorophores since a SPR dip does appear in the absorption band of the fluorophoresas seen in Fig. 4(a). More specifically, the intensity variation is understandablyrelated to the θi variation of the dip postion within the absorption band profile.

We turn next to the PL measurement at various detection angles while keepingthe pumping light at a fixed incident angle of 19◦ for both polarizations. The

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(b)

Fig. 6. PL spectra induced by (a) s-polarized light and (b) p-polarized light at various incidentangles (θi) and detected at θd = 0◦. The reference was obtained from the sample coated on flatsilver layer with the inset of (a) showing the measurement condition.

results are given in Figs. 7(a) and 7(b) for s- and p-polarization respectively withthe measurement condition described in the inset of Fig. 7(a). It is remarkable toobserve the hitherto unexpected resonant enhancement phenomenon observed forthe case with s-polarized incident light which even displays the same spectral featurefor p-polarized light presented in Fig. 7(b). In the light of indicated resonance effectobserved in both cases, an additional measurement was performed to determine

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Fig. 7. PL spectra observed at various detection angle, θd, when irradiated at incident angleθi = 19◦ for the (a) s- and (b) p-polarized incident lights. Also shown in the figure, the SPR dipsfor the same angles.

the relative compositions of s- and p-polarization components in the emitted PLfor both s- and p-polarized incident light. The results are presented in Fig. 8 forthe two cases of different incident wave polarizations with certain incident anglesof θi = 19◦ and detection angles of θd = 40◦. Each curve in the figure is codedas PiθiPeθd, representing the case of two incoming wave polarizations Pi (s- or p-)with certain incident angle θi and the corresponding PL wave components of eitherpolarization Pe (s- or p-) which is detected at θd. For illustrative purpose, only a

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633 nm;

Fig. 8. s- and p-polarized of PL spectra observed at detection angle, θd = 40◦, when irradiatedwith the s- or p-polarized incident light at incident angle, θi = 19◦. The s-polarized PL at flatsurface when irradiated with s-polarized incident light is included as reference.

typical case with certain θi and θd is given in Fig. 8. It is obvious that for eithers- or p-polarized incident light, the resonantly enhanced sharp PL spectral linesis dominantly p-polarized, displaying the resonant coupling of the fluorophore PLwith the p-polarized SPP as suggested earlier. But in the case of s-polarized incident

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light, it is the SPP induced by the randomly polarized PL emitted in broadly varieddirections instead of the SPP induced by the incident light. The angle dependentresonant peaks are the manifestation of the combined SPR and grating effect asexpressed by Eq. (2) which determines the θd as the angle θi in that equation. Thisalso naturally explains the disappearance of the sharp resonant PL line at θd = 0.

It is important to point out that the sharp emission lines shown in Fig. 7(a)for s-polarized incident light without the appearance of the SPR dips is in clearcontrast to the report by S. Wedge,27 which stated the absence of the same featurefor s-polarized light. The enhancement factor determined by comparing the peakintensities at given wavelengths relative to the reference intensities at the samewavelength has an average value of 6.0. On the other hand, the result presentedin Fig. 7(b) for p-polarized incident light clearly shows the perfectly matched SPPmodes with the resonantly enhanced PL emission modes from the fluorophores. Thisis in good agreement with previously reported results,26 indicating the effectiveresonant coupling between the SPP and the fluorophore emission. The averageenhancement factor was determined in the same manner for θd = 30, 35, and 40 forwhich the SPR dips occur in the oxazine PL spectrum. The average result was foundto be around 50.0 which is considerably larger than the value found for Fig. 7(a).

4. Summary

We have experimentally demonstrated that by using oxazine doped PMMA filmcoated with sinusoidal silver grating, we can observe resonant photoluminescenceenhancement phenomena for both s- and p-polarized incident light although theSPR dips of the incident light was only observable in the case of p-polarized incidentlight. It is further shown that the much larger enhancement factor of 50 found forthe case of p-polarized incident light is attributable to the combined contributionsof SPP enhanced absorption of excitation light and the resonant coupling betweenthe SPP and the fluorophore.

Acknowledgments

This work was supported by Osaka University Global COE “Center for ElectronicDevices Innovation” Program. The authors are also grateful to the Asahi GlassScholarship Foundation, especially Asahi Glass Thailand Foundation and AsahiGlass Indonesia Foundation, for the financial support.

References

1. C. W. Tang and S. A. Vanslyke, Organic electroluminescent diodes, Applied PhysicsLetters 51 (1987) 913–915.

2. C. Adachi, S. Tokito, T. Tsutsui and S. Saito, Electroluminescence in organic filmswith three-layer structure, Japanese Journal of Applied Physics 27 (1988) L269–L271.

3. J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Marks, K. Mackay,R. H. Friend, P. L. Burns and A. B. Holmes, Light-emitting diodes based on con-jugated polymers, Nature 347 (1990) 539–541.

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4. V. Y. Merritt and H. J. Hovel, Organic solar cells of hydroxy squarylium, AppliedPhysics Letters 29 (1976) 414–415.

5. C. W. Tang, Two layer organic photovoltaic cell, Applied Physics Letters 48 (1986)183–185.

6. Y. Liang, Z. Xu, J. Xia, S.-T. Tsai, Y. Wu, G. Li, C. Ray and L. Yu, For the brightfuture — bulk heterojunction polymer solar cells with power conversion efficiency of7.4%, Advanced Materials 22 (2010) E135–E138.

7. A. Tsumura, H. Koezuka and T. Ando, Macromolecular electronic device: Field effecttransistor with a polythiophene thin film, Applied Physics Letters 49 (1986) 1210–1212.

8. F. Garnier, R. Hajlaoui, A. Yassar and P. Srivastava, All-polymer Field-effect tran-sistor realized by printing techniques, Science 265 (1994) 1684–1686.

9. G. Horowitz, Organic field-effect transistors, Advanced Materials 10 (1998) 365–377.10. Y. Ohmori, K. Muro and K. Yoshino, Gas-sensitive and temperature-dependent Schot-

tky gated field effect transistors utilizing poly(3-alkylthiophene)s, Synthetic Metals 57(1993) 4111–4116.

11. C. Hagleitner, A. Hierlemann, D. Lange, A. Kummer, N. Kerness, O. Brand andH. Baltes, Smart single-chip gas sensor microsystem, Nature 414 (2001) 293–296.

12. C. Shan, H. Yang, J. Song, D. Han, A. Ivaska and L. Niu, Direct electrochemistry ofglucose oxidase and biosensing for glucose based on graphene, Analytical Chemistry81 (2009) 2378–2382.

13. N. E. Hecker, R. A. Hopfel, N. Sawaki, T. Maier and G. Strasser, Surface plasmon-enhanced photoluminescence from a single quantum well, Applied Physics Letters 75(1999) 1577–1579.

14. P. A. Hobson, S. Wedge, J. A. E. Wasey, I. Sage and W. L. Barnes, Surface plasmonmediated emission from organic light-emitting diodes, Advanced Materials 14 (2002)1393–1396.

15. J. Feng, T. Okamoto and S. Kawata, Enhancement of electroluminescence througha two-dimensional corrugated metal film by grating-induced surface-plasmon crosscoupling, Optics Letters 30 (2005) 2302–2304.

16. T. Liebermann and W. Knoll, Surface-plasmon field-enhanced fluorescence spec-troscopy, Colloids and Surfaces A: Physicochemical and Engineering Aspects 171(2000) 115–130.

17. S. Hayashi, Y. Yamada, A. Maekawa and M. Fujii, Surface plasmon-mediated lightemission from dye laser in reverse attenuated total reflection geometry, Japanese Jour-nal of Applied Physics 47 (2008) 1152–1157.

18. D. K. Gifford and D. G. Hall, Emission through one of two metal electrodes of anorganic light-emitting diode via surface-plasmon cross coupling, Applied Physics Let-ters 81 (2002) 4315–4317.

19. J. Kalkman, C. Strohhofer, B. Gralak and A. Polman, Surface plasmon polaritonmodified emission of erbium in a metallodielectric grating, Applied Physics Letters 83(2003) 30–32.

20. J. M. Pitarke, V. M. Silkin, E. V. Chulkov and P. M. Echenique, Theory of surfaceplasmons and surface-plasmon polaritons, Reports on Progress in Physics 70 (2007)1–87.

21. A. Gomez-Hens and M. P. Aguilar-Caballos, Long-wavelength fluorophores: Newtrends in their analytical use, Trends in Analytical Chemistry 23 (2004) 127–136.

22. W. L. Barnes, T. W. Preist, S. C. Kitson and J. R. Sambles, Physical origin of photonicenergy gaps in the propagation of surface plasmons on gratings, Physical Review B54 (1996) 6227–6244.

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23. A. P. Hibbins, W. A. Murray, J. Tyler, S. Wedge, W. L. Barnes and J. R. Sam-bles, Resonant absorption of electromagnetic fields by surface plasmons buried in amultilayered plasmonic nanostructure, Physical Review B 74 (2006) 073408.

24. B. J. Matterson, J. M. Lupton, A. F. Safonov, M. G. Salt, W. L. Barnes and I. D.W. Samuel, Increased efficiency and controlled light output from a microstructuredlight-emitting diode, Advanced Materials 13 (2001) 123–127.

25. Y. Fujiwara, K. Murata, M. Ojima, Y. Ogawa, H. Kubo, H. Yoshida, A. Fujii andM. Ozaki, Surface plasmon enhanced photoluminescence on biharmonic grating struc-ture, Journal of Nonlinear Optical Physics & Materials 19 (2010) 571–581.

26. K. Murata, M. Ojima, Y. Ogawa, Y. Fujiwara, H. Kubo, A. Fujii and M. Ozaki, Fluo-rescence enhancement of conducting polymer coated on biharmonic metallic grating,Applied Physics Express 3 (2010) 041601.

27. S. Wedge, I. R. Hooper, I. Sage and W. L. Barnes, Light emission through a corrugatedmetal film: The role of cross-coupled surface plasmon polaritons, Physical Review B69 (2004) 245418.

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