Pengantar dari Ketua Himpunan Optika Indonesiainos.indonesianoptics.org/files/Bulettin/Buletin_InOS_Vol_5_No_1...di UPH dan LIPI, serta Seminar Laser ... teoritis scattering sebatang

Himpunan Optika Indonesia menerima sumbangan berita yang berkaitan dengan optika dari para anggota untuk dimuat pada Buletin HOI. Informasi tersebut dapat dikirimkan ke:

[email protected]

Vol. 5, no. 1 , Juni 2016

Himpunan Optika Indonesia

Majelis Himpunan Rahmat Hidayat (Ketua) Alexander A. Iskandar (Mantan Ketua BPP Terakhir) Tjia May On Fitrilawati Henri P. Uranus Husin Alatas Maria M. Suliyanti K. Hendrik Kurniawan

Badan Pengurus Pusat Himpunan Ketua BPP : Henri P. Uranus Wakil Ketua Terpilih : Husin Alatas Sekretaris Eksekutif : Maria M. Suliyanti Bendahara : K. Hendrik Kurniawan BULETIN HOI ISSN 2407-683X

Diterbitkan oleh Himpunan Optika Indonesia (HOI)

Penanggung Jawab Henri P. Uranus Pimpinan Redaksi Husin Alatas

Anggota Redaksi Alexander A. Iskandar, Indra Karnadi, Ismudiati P. Handayani

UNTUK KALANGAN SENDIRI

Buletin HOI adalah media komunikasi antar anggota Himpunan Optika Indonesia (HOI)

Pengantar dari Ketua Himpunan Optika Indonesia

Selamat bertemu kembali dalam Buletin Himpunan Optika Indonesia Vol. 5, No. 1 ini.

Edisi ini menyajikan berita jalannya beberapa lokakarya dan konferensi ilmiah yang terkait dengan bidang optika, yaitu LINOF 2016, WCRO 2016 di UPH dan LIPI, serta Seminar Laser dan Nanofotonika di IPB. Selain itu, disajikan juga informasi beberapa konferensi ilmiah yang terkait dengan bidang optika dalam waktu dekat, yaitu ISPhoA 2016 di Bali, COMNETSAT 2016 di Surabaya, dan icOPEN 2016 di Chengdu, China.

Pada edisi ini, disajikan juga sharing hasil penelitian anggota dalam bentuk ringkasan makalah Azrul Azwar et al di JNOPM tentang studi teoritis scattering sebatang nanowire yang bersifat disipatif dan dispersif, serta makalah Didit Yudistrira et al. tentang fenomena kopling phonon-polariton pada cavity surface phonon yang dibuat dari phononic crystal berbasis material lithium niobate.

HOI juga menyambut hangat dan mengucapkan selamat bergabung kepada beberapa anggota baru.

Sebagai media komunikasi antar anggota, Buletin HOI sangat mengharapkan kontribusi dari pembaca dengan mengirimkan informasi berita maupun artikel yang relevan. Untuk itu, ditunggu kiriman materi baik berupa artikel atau berita dari anggota untuk edisi-edisi berikutnya.

Selamat membaca.

Henri P. Uranus

Daftar Isi Pengantar dari Ketua HOI 1 Berita Kegiatan Ilmiah dan Konferensi 2 Berita Anggota 4 Laporan Singkat Hasil Riset Anggota HOI 7

BULETIN HOI (ISSN 2407-683X) Vol. 5, no. 1, Juni 2016

2

BERITA KEGIATAN ILMIAH DAN KONFERENSI

LINOF 2016 and WCRO 2016

InOS was a co-sponsor of Lokakarya Ilmiah Nasional Aplikasi Optik dan Fotonik (LINOF 2016) and International Workshop on Convergence of Radio and Optical Technologies (WCRO 2016). LINOF 2016 was organized by Research Center for Physics (P2F), the Indonesian Institute of Sciences (LIPI) in collaboration with Dept. Electrical Eng., Pelita Harapan University (UPH). WCRO 2016 was co-organized by the National Institute of Information and Communications Technology (NICT), Japan, LIPI, and UPH. These two events were blended into a joint workshop which took a theme of “Radio and Optical Technologies for Sensor Networks”. The WCRO 2016 was under the auspice of Ministry of Internal Affairs and Communications, Japan and technically sponsored by The Indonesian Optical Society (InOS), The OSA Indonesia Section, The IEEE Indonesia Section, and IEEE Region 10 Ad-Hoc Committee on Entrepreneurship, Innovation and Internships Chair.

LINOF 2016 was held on 7 March 2016. The workshop was attended by 77 participants from various universities and research centers in Indonesia. The workshop started in UPH Campus in the morning, where 3 speakers equipped the audience with theory. Nursidik Yulianto, MT from Research Centre for Physics, LIPI explained the generation of microwave signal by beating 2 lasers with slightly different wavelengths. Thermo optic effect was used as the tuning tools. Dr. Isnaeni from LIPI then explained about photoluminescence including the quantum confinement effect. Tomi B. Waluyo, M.Eng.Sc also from LIPI then explained the fiber Bragg grating and how to use it for sensing, including the use of interrogator for reading the status of sensor networks. The sessions were constructive with many questions from the audience. After the theory session, the audiences were taken to Research Centre for Physics, LIPI in Puspiptek, Serpong by 2 buses. There, the audience were grouped in 3 groups which moved from one lab to another to get hand-on experience on the three topics: microwave generation using beating of 2 lasers, photoluminescence of several liquids, including olive oil and FBG for sensors.

The theoretical session of LINOF 2006

The experimental session of LINOF 2006

WCRO 2016 was held on 8 March 2016. The sessions fully took place in UPH Campus, Tangerang. The workshop was attended by 87 participants from various universities and research centers in Indonesia. A team of Japanese professors and researchers joint the workshop as organizers and speakers. The workshop started with 2 keynote talks, i.e. on Convergence of Radio and Lightwave Technology for Public Infrastructure by Prof. T. Kawanishi from Waseda University, Japan, and in Research on Optics and Photonics in Indonesia by Dr. Husin Alatas from Bogor Agricultural University (IPB) Indonesia and The Indonesian Optical Society (InOS). After that, there are 7 invited talks by Japanese and Indonesian researchers. Dr. Michitaka Ameya from AIST Japan on Antenna and RCS Callibration, Tomi B. Waluyo, M.Eng.Sc. from LIPI Indonesia on Optical Fiber Extensometer, Dr. Naruto Yonemoto from ENRI Japan on Millimeter-wave Radar System on Optical Fiber Networks, Mashury, M.Eng. from LIPI Indonesia on Indonesian Surveillance Radar (ISRA) System, Prof. Eddy Hermawan from National Institute of Aeronautics and Space (LAPAN) Indonesia on Study on Equatorial Atmosphere/Ionosphere using Radar, Dr. Henri Uranus from UPH and InOS Indonesia on Slowlight for Photonic


3

Sensing, and Prof. Shintaro Hisatake from Osaka University Japan on THz Radio Visualization using Photonics Technology. The sessions were productive with many interesting questions from the audience.

Group photo of the WCRO 2016

Keynote talk by Prof. T. Kawanishi from Waseda University Japan

Keynote talk by Dr. Husin Alatas from Bogor Agricultural University Indonesia.

LINOF 2016 (sesi September) Setelah mengadakan LINOF 2016 pada 1 Maret 2016, Pusat Penelitian Fisika LIPI akan mengadakan kembali Lokakarya Ilmiah Nasional Aplikasi Optik dan Fotonik (LINOF) 2016 pada 6 September 2016 di Puspiptek Serpong. HOI mendukung penyelenggaraan lokarya tsb. Biaya registrasi untuk pemakalah adalah gratis. Informasi lebih lanjut dapat dilihat di http://situs.opi.lipi.go.id/seminarlinof2016/ icOPEN 2016

The International Conference on Optical and Photonic Engineering (icOPEN) 2016 will be held on 26-30 September 2016 in Chengdu, China. This conference will be organized and hosted by OPSS (Optics and Photonics Society of Singapore), sponsored by Sichuan Institute of Electronics, Sichuan University, University of Electronic Science and Technology of China, Southwest Jiaotong University and Chengdu University of Information Technology. The Indonesian Optical Society (InOS) will be supporting the conference. InOS member will get 10% discount on the registration fee. For further information, please check the website at http://www.icopen.net.

ISPhOA 2016

Institut Teknologi Sepuluh Nopember, Surabaya kembali mengadakan International Seminar on Photonics, Optics and its Applications (ISPhOA) 2016 di Bali pada tanggal 24-25 Agustus 2016, setelah sebelumnya di tahun 2014 telah sukses menyelenggarakan kegiatan yang sama. HOI mendukung sepenuhnya kegiatan tersebut dan bagi anggota HOI, panitia memberikan potongan harga khusus sebagai berikut: untuk anggota lokal HOI memperoleh potongan biaya registrasi: 40% (early bird), dan 28.5% (normal), sedangkan untuk anggota HOI luar negeri: 11.1 % (early bird) dan 10% (normal). Informasi lebih lengkap bisa dilihat di http://www.isphoa2016.org.

IEEE COMNETSAT 2016

The IEEE Communication Network and Satellite Conference 2016 (COMNETSAT 2016) will be held on 8 – 10 Dec. 2016 in Surabaya. The conference will be hosted by IEEE Communications Society Indonesia Chapter and Institut Teknologi Sepuluh Nopember. In the conference, there will a track on Broadband and Photonics. For further information, please check the website http://comnetsat.org.


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Seminar Bilateral Laser & Nanofotonika Departemen Fisika IPB-Puslit Fisika Lipi Pada tanggal 27 April 2016 Departemen Fisika IPB bersama Puslit Fisika Lembaga Ilmu Pengetahuan Indonesia (LIPI) mengadakan Seminar Bilateral pertama mengenai Laser & Nanofotonika yang diselenggarakan oleh mahasiswa S2 Biofisika Departemen Fisika IPB. Seminar Bilateral menghadirkan lima pembicara yang membawakan topik tentang penelitian optika state of the

art yang pernah dan sedang menjadi kajian riset aktif di kelompok kerja masing-masing. Kelima pembicara tersebut merupakan anggota HOI yakni Dr. Maria Suliyanti, Dr. Husin Alatas, Dr. Isnaeni, Dr. Hendradi Hardhienata serta Dr. Yulianti Herbani.

Seminar Bilateral ini bersifat terbuka untuk publik dengan peserta mayoritas mahasiswa fisika Depertemen Fisika IPB dan berlangsung di Auditorium FMIPA IPB. Acara dibuka pada pukul 8.15 oleh Ketua Departemen Fisika IPB Dr. Akhiruddin Maddu dilanjutkan dengan diskusi panel sesi pertama yang menghadirkan dua pembicara dari LIPI yakni Dr Isnaeni dan Dr. Maria Suliyanti serta dimoderatori oleh dosen Fisika IPB Dr. Setyanto Tri wahyudi. Dalam kesempatan tersebut Dr. Isnaeni membawakan presentasi mengenai “Sintesis dan Aplikasi Quantum Dot” kemudian dilanjutkan dengan presentasi oleh Dr. Maria Sulyanti yang memaparkan topik mengenai “Laser-Induced Breakdown Spectroscopy (LIBS)”. Beberapa diskusi menarik yang mengemuka di antaranya mengenai prospek pengembangan penelitian kuantum dot dan LIBS di Indonesia terutama peluang kerjasama antar Puslit LIPI yang telah mengembangkan penelitian eksperimental dengan Departemen Fisika IPB yang memiliki kompetensi dalam bidang biofotonika dan teori biofisika kuantum misalnya dalam bentuk penelitian bersama yang melibatkan mahasiswa IPB.

Para pembicara bersama Dosen Fisika IPB

Sesi panel kedua menghadirkan tiga pembicara yakni Dr. Yuliati Herbani yang membawakan presentasi mengenai “Sintesis material nanopartikel dengan teknik laser ablation”, kemudian dilanjutkan dengan paparan Dr. Husin Alatas mengenai “Permodelan Piranti Fotonika”, dan Dr. Hendradi Hardhienata yang berbicara mengenai “Karakterisasi Permukaan Material Nanostruktur.” Sesi kedua dalam diskusi panel yang dimoderatori oleh Dr. Yessie Widya Sari dari IPB terjadi diskusi menarik di antaranya mengenai penemuan gravity wave belum lama ini oleh tim peneliti LIGO yang menggunakan teknologi berbasis interferensi optik dan pembahasan mengenai keunggulan metode optika nonlinier dalam karakterisasi permukaan material secara real time dan nondestruktif. Di akhir seminar, panitia mengundang beberapa peserta seminar untuk mengemukakan kesan dan pesan yang diperoleh dari seminar. Secara umum peserta merasakan nuansa ilmiah yang positif serta memperoleh manfaat dalam bentuk bertambahnya wawasan mengenai perkembangan nanofotonika dan the art of scientific research hingga mencapai publikasi internasional.

BERITA ANGGOTA Himpunan Optika Indonesia (HOI) sebagai suatu himpunan profesi, tentu saja merupakan wadah komunikasi dan wadah untuk merintis kerjasama antara para Anggotanya. Di pihak lain, HOI juga harus melayani dan memberikan nilai tambah kepada para Anggotanya. Salah satu bentuk layanan dan nilai tambah yang dapat diberikan HOI adalah untuk setiap kegiatan ilmiah yang diselenggarakan oleh pihak lain yang mendapatkan dukungan dari HOI, maka HOI selalu mengusahakan agar Anggota HOI yang mengikuti kegiatan ilmiah tersebut mendapatkan perlakuan khusus, misalnya


5

potongan biaya keikutsertaan. Layanan lainnya adalah penerbitan Buletin HOI ini sebagai media komunikasi antar Anggota HOI.

Seperti yang telah tertera dalam Anggaran Dasar dan Anggaran Rumah Tangga HOI, keanggotaan HOI terdiri dari

• Anggota Utama adalah seseorang yang memiliki kontribusi ilmiah seminal yaitu publikasi ilmiah berdampak dalam bidang berkaitan dengan optika yang ditunjukkan oleh jumlah sitasi dari beberapa publikasi yang signifikan dan berdasarkan keputusan Majelis. Anggota Utama ini diusulkan oleh setidaknya 5 orang Anggota Penuh secara tertulis dengan menyertakan argumentasi bagi pertimbangan oleh Majelis.

• Anggota Penuh adalah sarjana yang telah

menunjukkan rekam jejak penelitian dalam bidang optika yang dipatenkan secara internasional atau dipublikasikan di jurnal internasional yang tercantum dalam daftar lembaga pengindeks sitasi internasional. Majelis menyetujui penerimaan Anggota Penuh baru setelah pemeriksaan rekam jejak penelitian dalam bidang optika ybs yang diukur dengan jumlah artikel dalam jurnal internasional yang memiliki impact factor atau SNIP minimal 0,1.

• Anggota Muda adalah lulusan program pendidikan

sarjana S1 yang tertarik dan terlibat dalam kegiatan bidang optika. Majelis menyetujui penerimaan Anggota Muda baru setelah pemeriksaan rekam jejak keterlibatan ybs dalam bidang optika ditandai dengan pernah melakukan presentasi yang berkaitan bidang optika dalam pertemuan ilmiah setidaknya pada tingkat nasional atau telah 3 tahun bekerja dalam bidang optika.

• Anggota Kehormatan adalah seorang tokoh

masyarakat yang telah memberikan kontribusi luar biasa pada perkembangan ilmu pengetahuan dan teknologi dalam bidang optika. Pengangkatan Anggota Kehormatan ini dapat diusulkan oleh Majelis atau BPP atau sedikit-dikitnya 10 Anggota dan diputuskan oleh Majelis berdasarkan laporan tim pemeriksa yang dibentuk BPP.

Status keanggotaan ini berlaku seumur hidup untuk Anggota Utama dan Anggota Kehormatan, sedangkan Anggota Penuh dan Anggota Muda, status ini diperpanjangan secara otomatis dengan pembayaran iuran tahunan.

Untuk memastikan bahwa layanan dan nilai tambah di atas dapat dinikmati oleh para Anggota HOI, maka status keanggotaan HOI tersebut patut mendapatkan perhatian

dari para Anggota HOI. Seperti yang tertuang dalam Anggaran Rumah Tangga HOI, keanggotaan seseorang dalam Himpunan Optika Indonesia (HOI) dapat berakhir oleh karena

i. meninggal dunia ii. atas permintaan sendiri iii. tidak membayar iuran selama 4 tahun berturut-turut iv. melakukan tindakan tidak terpuji

Pemberhentian Anggota ini diputuskan oleh sidang Majelis berdasarkan usulan dari BPP.

Seorang Anggota Muda HOI dapat saja mengusulkan perubahan status keanggotaannya menjadi Anggota Penuh melalui prosedur seperti yang telah diatur dalam penerimaan Anggota Penuh. Pelantikan Dr. Eng. Erning Wihardjo

sebagai Rektor Ukrida

Anggota HOI, Dr. Eng. Erning Wihardjo dilantik menjadi Rektor Universitas Universitas Kristen Krida Wacana (UKRIDA) untuk perioda 2016-2020 pada tanggal 29 Januari 2016. HOI turut bangga dan mengucapkan selamat berkarya untuk Dr. Eng. Erning Wihardjo.

Upacara pengukuhan Dr. Eng. Erning Wihardjo sebagai rektor universitas UKRIDA.

.


6

Ucapan selamat dari HOI atas pengukuhan Dr. Eng. Erning Wihardjo sebagai rektor universitas UKRIDA.

Anggota baru

HOI mengucapkan selamat bergabung kepada anggota-anggota baru sbb.:

• Dwi Bayuwati (Pusat Penelitian Fisika, LIPI), no anggota: 3 2016 16 0072

• Ian Yulianti (Univ. Negeri Semarang), no. anggota: 2 2016 13 0073

Ditunggu kiprah dan partisipasi dari anggota-anggota baru tsb. dalam aktifitas untuk memajukan dunia optika di Indonesia.

Nomor Anggota mempunyai format s yyyy rr nnnn memiliki arti sebagai berikut :

• s : status keanggotaan (1: Anggota Utama, 2: Anggota Penuh, 3 : Anggota Muda)

• yyyy : tahun diterima sebagai Anggota • rr : kode provinsi • nnnn : nomor Anggota

Iuran Anggota tahun 2016 Dengan berakhirnya masa berlaku kartu Anggota HOI pada tahun 2015, maka perlu diterbitkan kartu anggota yang baru untuk tahun 2016. Untuk itu semua Anggota HOI diharapkan melunasi iuran Anggota yang berdasarkan ketentuan Majelis HOI, di mana seorang Anggota Penuh diwajibkan untuk melunasi iuran tahunan sebesar Rp. 300.000,- (tiga ratus ribu rupiah) dan Rp. 100.000,- bagi Anggota Muda. Iuran Anggota tersebut dapat ditransfer kepada rekening HOI dengan data sebagai berikut :

Bank : BCA, KCU Mangga Dua Raya, Jakarta

Nama Rekening : Himpunan Optika Indonesia Nomor Rekening : 335 3333336

Setelah Bendahara melaporkan diterimanya pembayar-an iuran tahun 2016 tersebut, kartu Anggota akan dicetak dan dikirimkan ke alamat masing-masing Anggota yang telah membayar. Untuk membantu mempercepat pencatatan penerimaan iuran Anggota tahun 2016 ini, mohon para Anggota yang telah membayar iuran ini mengirimkan bukti pembayaran ke alamat email HOI ([email protected]).

HOI mengucapkan terima kasih kepada anggota yang telah membayar iuran 2016. Kartu keanggotaan untuk

anggota yang sudah membayar sedang dalam proses pencetakan dan pengiriman.


7

Fano-like spectral profile in TE wave

scattering by nanowire of dissipative and

dispersive materials

Azrul Azwar1,2, Agoes Soehianie1, Alexander A.

Iskandar1,* and May-On Tjia1

1 Physics of Magnetism and Photonics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia 2 Department of Physics, Faculty of Mathematics and Natural Sciences, Tanjungpura University, Pontianak 78115, Indonesia

Journal of Nonlinear Optical Physics and Materials 25(1), 1650005 (2016)

DOI: 10.1142/S0218863516500053

Keywords: Fano resonance; asymmetric lineshape; surface plasmon; light scattering; nanowire

This paper presents the result of a study on Fano phenomena in the TE wave scattering by a nanowire having complex and dispersive permittivities ε1(ω) = ε'1(ω) + iε"1(ω) with σ = 0 and σ ≠ 0.

Previous studies were mostly focused on the cases of ε"1 = 0 with large ε1 (ε1 = 50) and σ = 0, which exhibit cascaded resonance profiles of periodically varying asymmetry for increasing size parameter of the nanowire. It is shown that the spectral profiles of scattering coefficients are sensitively affected by the imaginary part of the permittivity and its overall frequency dependent properties. The cascaded resonance profile reported previously for real and positive permittivity is shown to be suppressed by a large ε"1 while the spectral profile is broadened by the dispersive nature of ε1(ω) which also increases the asymmetry of the profile. The negative sign of the real part of the permittivity, except for ε'1 = −1, is generally found to eliminate the resonance profile. This study also shows distinctly different Fano phenomena in the case of metal (or specifically silver) nanowire. Specific scattering coefficients calculated for silicon (Si) and silver (Ag) nanowire using experimental data of corresponding ε1(ω) are demonstrated to exhibit the spectral profiles for certain wire sizes with nicely fitted Fano profile.

Referring to Fig. 1, the complex coefficients in the

multipole expansions of the scattered (am) and internal (bm) magnetic fields, are obtained from solving the boundary condition to yield respectively,

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )122211

211122

ερ

εεερ

εε

ερ

εεερ

εε

xJxHxHxJ

xJxJxJxJ

a

mmmm

mmmm

m

∂∂

−∂∂

∂∂

−∂∂

=(1)

Fig. 1. A schematic description of the single nanowire and the TE-wave scattering configuration with ε2 = 1..

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )122211

221221

ερ

εεερ

εε

ερ

εεερ

εε

xJxHxHxJ

xJxHxHxJ

b

mmmm

mmmm

m

∂∂

−∂∂

∂∂

−∂∂

=(2)

with x = 2πr/λ, while Jm and Hm are the Bessel function of the first kind and the Hankel function of the first kind respectively. These expressions can be related as follows

( )

( )

( )

( )

2

2

2

21

122

∂∂∂∂

−+

∂∂∂∂

=ε

ρ

ερ

ερ

ε

ερ

ε

xH

xJ

b

xH

xJ

a

m

m

m

m

m

m

(3)

where the left hand-side represents the Fano resonance profile, the first and second terms inside the absolute value sign on the right-hand side represent the narrow resonance and the slowly-varying background, respectively. The above equation can be recast into

mmmmm ZYbXa ++=2222 (4)

with,

LAPORAN SINGKAT HASIL RISET ANGGOTA HOI


8

( )

( )

( )

( )( )( ) ( ) ( )

mmmmmmm

m

m

m

m

m

m

YbXYbXZ

xH

xJ

Y

xH

xJ

X

**

2

2

21

12

,

+=

∂∂∂∂

−=

∂∂∂∂

=ε

ρ

ερ

ερ

ε

ερ

ε

The generalized Fano resonance intensity lineshape is given by [1]

2

)()(

2

2

)()(

)1(1

)()( ωφ

ωφ

ωω

ηηω B

A

ii

bg eBi

eAI

qI +

Ω+=

−+

Ω+Ω+

= (5)

where, q is the asymmetry parameter (Fano parameter), Ω is a dimensionless frequency defined by Ω = (ω − ω0)/(Γ/2), where ω0 and Γ are the frequency and width of the narrow resonance, respectively. The parameter η denotes the fraction of the background intensity, Ibg, that contributes to the interference between the scattered waves of narrow and broad spectral profiles. Further, A(ω), B(ω), φA(ω), and φB(ω) are taken as real functions with negligible variation around the resonance frequencies. Since Eq. (3) is supposed to hold for all m (multipole order), the scattering efficiency

∑∞

−∞=

=m

msca ax

Q22

(6)

is expressed as the sum of infinite series of Fano resonances with their lineshapes given by the generalized Fano formula, Eq. (5).

It should be noted here that the narrow resonance is defined by |bm|2 in Ref. 2, but it is replaced by |Xm|2|bm|2 in the present analysis based on Eq. (4). For the nondispersive materials with positive value of permittivity, |X0|2 has its maximum and minimum positions exactly occurring at the corresponding positions of |b0|2 and thereby Lorentzian profile is preserved by |X0|2|b0|2. As it turns out, the much smaller value of |X0|2 suppresses the large value of |b0|2 to the same magnitude of unity. This result together with the plots of each terms in Eq. (4) are presented in Fig. 2 below which also shows the resulted Fano profile of |a0|2 as shown in Ref. 1. It is seen in this figure that |a0|2 is explicitly composed of narrow resonance (|Xm|2|bm|2), slowly-varying background (|Ym|2) and the crossterm (Zm), with |a0|2 being expressed as a simple sum of the three components, make it easier to visualize the individual contribution to |a0|2.

Fig. 2. Profile of |a0|2 (solid) and the contributing components of

narrow resonance |X0|2|b0|

2 (dotted lines), slowly-varying background (dash) and the cross-terms (dashdot). The incident wave has a

wavelength range of 50–5000 nm, the nanowire considered has a radius r = 50 nm and permittivity ε1 = 25.

The cascaded pattern as also discussed in Refs. 1 and 2 for large value of ε1 can be traced to the nature of Bessel function in the narrow resonance term in Eq. (3).

In the case of dielectric materials having complex permittivity, the Bessel function in Eqs. (1) and (2) will have a real and imaginary parts, denoted by Re[Jm] and Im[Jm], respectively. The narrow resonance still have a Lorentzian properties with the peaks remaining closely related to the zeros of Re[Jm] as in the nondissipative case. On the other hand, Im[Jm] is found to oscillate with increased amplitude at the higher frequencies, which is responsible for the broadening and decreasing amplitude of the resonance profile. In the meantime, the cross-term also decreases with increased frequency, leaving the slowly-varying background taking over the dominant contribution to the scattering efficiency and weakening the resonance feature. As a consequence, the minimum value of the Fano lineshape does not always touch the zero base line as shown in the nondissipative case and the cascaded resonance profile reported previously is suppressed by a large ε1.

We turn next to a realistic case of dissipative and dispersive permittivity. Specifically, we consider silicon (Si) nanowire with the permittivity given by experiments taken from Ref. 3. In this case, the narrow resonance component vanishes rapidly due to the rapidly increasing imaginary part of the permittivity in the high frequency region. Being a product of narrow resonance and background, the cross-term is also seen to decrease correspondingly. As a result, only one Fano resonance profile in the scattering efficiency spectrum can be expected in this case (Fig. 3). It is found that the resulted |a0|2 fits the Fano lineshape given by Eq. (5) with asymmetry parameter q = 4.254, and η = 0.8855 indicating a nearly full background contribution to the interference between narrow and broad spectral profiles. The


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coefficient of determination attained in this case is given by R2 = 0.996.

Fig. 3. Data points are calculated spectrum of |a0|

2 using Eq. (3), the solid red line is the best fitted profile of |a0|

2 to the Fano lineshape given by Eq. (5).

We present next, the extended study of scattering by

a silver (Ag) nanowire. The scattering coefficient calculated according to the formulation given in Eq. (6) for a number of individual modes are presented in Fig. 4 for r = 30nm in the frequency range covered by experimental data of Johnson–Christy [4]. In contrast to the dielectric nanowire, one observes that only a single resonance peak appearing in the frequency range where cascaded resonance profile are found in the case of dielectric nanowire with high permittivity (ε1 = 50) as reported in Ref. 2. Additionally, as observed in Fig. 4, only |a1|2 contributes to the scattering efficiency instead of four of the lowest multipole modes |a0|, |a1|, |a2|, and |a3| found in the dielectric case. It is also interesting to add that in the case of dielectric nanowire, the resonance peak frequency undergoes redshift with increased nanowire radius, which is understood to be related to the cavity effect. On the other hand, the resonance in the case of metallic nanowire is related to the plasmon resonance and hence the resonance frequency remains relatively unchanged with respect to variation of nanowire radius.

Fig. 4. Plots of the six lowest mode of silver nanowire with radius r =

30 nm.

It is found that as in the dielectric case, the scattering

coefficient of silver nanowire can also be described as the result of interference between the narrow resonance and slowly-varying background, but in contrast to the dielectric nanowire, one observes that the lineshape of the narrow resonance is not simply described by the Lorentzian curve. This non-Lorentzian property is related to the frequency dependent silver permittivity. Figure 5 shows the scattering coefficient |a1|2 of silver nanowire with radius r = 30 nm. It is found that spectral profile fits the Fano lineshape given by Eq. (5) with asymmetry parameter q = −3.985 and η = 0.997 indicating a nearly full background contribution to the interference between narrow and broad spectral profiles. The coefficient of determination attained in this case is given by R2 = 0.988.

Fig. 5. The bold blue line is calculated spectrum of the scattering coefficient |a1|

2 of silver nanowire with radius r = 30 nm. The red thin line is the best fit profile of |a1|

2.

To conclude, we have analyzed the TE-polarized light

scattering by a nanowire having complex and dispersive permittivities. We showed that the spectral coefficients profile are sensitively affected by the dissipative and dispersive character as well as the radius of the nanowire. The dissipative character suppresses the narrow resonance, and further eliminates the cascaded resonance as found in nondissipative case, while the dispersive character of nanowire produces the non-Lorentzian lineshape of the narrow resonance. It is demonstrated that Fano-like spectral feature are still found in the real case of silicon and silver nanowire of certain radii, with nicely fitted Fano lineshape. It is further shown that the cavity effect and the surface plasmon resonance, respectively, are responsible for the narrow resonance contribution to the corresponding scattering coefficients. Acknowledgment


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This work was supported by Program Desentralisasi DIKTI 2015 from the Indonesian Ministry of Education and Culture (Contract No. 310q/I1.C01/PL/2015). Selected References [1] M. V. Rybin, I. S. Sinev, K. B. Samusev and M. F.

Limonov, Phys. Solid State 56(3) (2014) 580–587. [2] M. V. Rybin, K. B. Samusev, I. S. Sinev, G.

Semouchkin, E. Semouchkina, Y. S. Kivshar and M. F. Limonov, Opt. Exp. 21 (2013) 30107.

[3] E. D. Palik, Handbook of Optical Constant of Solids (Academic Press, 1985).

[4] P. B. Johnson and R. W. Christy, Phys. Rev. B6 (1972) 4370.

Phonon-Polariton Entrapment in Homogenous Surface Phonon Cavities

Didit Yudistira*, Andreas Boes, Benjamin Dumas, Arnan Mitchell School of Electrical and Computer Engineering, RMIT University, Melbourne, VIC, 3001, Australia ARC Centre of Excellence for Ultrahigh Bandwidth Devices and Optical Systems (CUDOS) *[email protected]

Amgad R. Rezk1, Leslie Y. Yeo1, Morteza Yousefi1, Bahram Djafari-Rouhani2 1Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC, 3001, Australia 2Institut d’Electronique, de Micro electronique et de Nanotechnologie (IEMN), UMR CNRS 8520, Universit e de Lille 1, 59655 Villeneuve d’Ascq Cedex, France Ann. Phys. (Berlin) 528 (5), 365-372(2016) DOI: 10.1002/andp.201500348

Abstract— Surface phonon cavity formed by the placement of a defect of a single domain within periodic domain inversion of single crystal piezoelectric lithium niobate exhibiting surface phononic bandgap through the phonon-polariton coupling is introduced. It is shown that the proposed cavity can exhibit entrapment of phonon-polariton, indicated by the simultaneous localization of both surface phonons and the electric within the defect.

Keywords—phononic crystals; phonon-polariton; domain inversion; lithium niobate

Phononic bandgap structures and phononic crystals are novel class of materials, which have emerged as

promising candidates to control the suppression and redirection of phonon propagation in controlled, given rise by their unique properties, namely phononic bandgaps. Reports have shown that if a defect is embedded within a phononic bandgap structure, a phonon cavity can be formed, enabling the trapping and concentration of phonons of a specific resonant frequency in a desired location. In previous recent work, we have demonstrated that surface phononic bandgap can be achieved in a material that is mechanically, electromechanically, and topographically homogeneous, without any physical alteration of the surface, but simply formed by periodically reversing the sign of the piezoelectric tensor e in single crystal lithium niobate [1–3]. The bandgap is exhibited through phonon-polariton coupling, yielding the simultaneous suppression of the propagation of both the surface phonons and the accompanying electric field in a specific frequency range, determined by the structure period a.

In this communication, we introduce a surface phonon cavity achieved by placement of a defect of a single domain within a one-dimensional periodic domain inversion of a single crystal piezoelectric lithium niobate. We demonstrate that the proposed cavity can exhibit entrapment of phonon-polariton, indicated by the simultaneous spatial localization of both the surface phonons and the electric fields within the defect. To our best knowledge, this is the first report showing the formation of a surface phonon-polariton cavity, and is further distinguished from previous work by its demonstration on a homogenous material.

An illustration of the structure and a micrograph of the

Figure 1. (a) A surface phonon cavity with a bandgap structure consisting of

regular poling with period a, and with an included defect of width D, probed

with surface acoustic wave (SAW) (from the left) (b) Microscope image of the

fabricated surface phonon cavity and the IDTs used to generate the SAW.

Laser Doppler Vibrometry (LDV) visualization of the transmitted SAW is

conducted on the far side of the defect as indicated by the spot on which the

laser beam is focused.

fabricated structure are shown in Figures 1a and 1b, respectively. The cavity consists of a defect of unpoled material with a lateral width D placed at xc = A within a


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phonon-polariton bandgap structure as illustrated in Figure 1a. A bandgap structure with a period a = 20 µm is considered, which corresponds to surface phononic bandgap at around 185 MHz as revealed by the calculated surface phononic band structure (see Figure 2a) of an infinitely long periodic structure (displayed in the inset). To reveal the surface cavity resonance excitation as well as to gain insight into its resonant behavior, we calculate the frequency spectra of the amplitude response of the surface phonon displacement |U|, which is determined on the defect area at xc = A, while varying the defect width D from 0.5a to 1.0a

Figure 2. (a) Surface phononic band structure for an infinite sequence of

periodic domain inversions with period a = 20 µm. (b) Simulated map of the

spectral response of the surface phonon displacement |U| as a function of

the frequency and defect width D. (c) Simulated spectral responses of the

surface phonon displacement |U| of the cavities with different defect

widths; (top) non-defect structure (D = 0.5a = 10 µm); (middle) cavity with

width D = 0.75a = 15 µm, and, (bottom) a cavity with width D = 1.0a = 20 µm.

(d) Corresponding displacement profiles within the cavity (illustrated by the

inset), calculated at peaks (i, ii, vi) and (iii, iv and v) and at vii, showing an

evanescent wave characteristic associated with the bandgap.

Figure 2b shows the contour of the calculated |U| in the frequency and defect width D space, revealing a distinct peak that traverses the bandgap as D varies from 0.5a to 1.0a or from 10 nm to 20 nm. As an example, we plot in Figure 2c for three different defect widths, D = 0.5a = 10 µm, 0.75a = 15 µm and 1.0a = 20 µm, where we clearly observe distinct peaks located at the edges and within the bandgap, denoted by (i ii, vi), and (iii, iv, vi), respectively. Peaks iii, iv, and vi can thus be ascribed to surface cavity resonances, verified by the corresponding displacement plots in Figure 2d. This cavity resonance originates from the surface phonons that are trapped by the defect and that oscillate back and forth within it while

decaying outside the defect. As indicated by Figure 2b, the frequency of the cavity resonance decreases as the D increases, because the trapped surface phonons have more space to oscillate. This may suggest that the frequency of the cavity resonance can be tuned through the modulation of the defect width D.

To experimentally demonstrate the above results, four samples are prepared: unpoled lithium niobate (sample 1); a non-defect sample (or phononic bandgap structure) (sample 2) and two cavity samples with different defect widths, D = 15 µm (sample 3) and D = 20 µm (sample 4), respectively. Sample characterization is performed using a standard interdigital transducer (IDT) generating coherent SAW with a frequency that can be tuned between 175 – 195 MHz spanning the phononic bandgap in conjunction with the use of a laser Doppler vibrometer (LDV) to directly measure the surface phonon displacement |U| on the defect area. Figure 1b shows the characterization setup used in our experiment.

Figure 3. Measured spectral

response of the surface

displacement |U| obtained

with the LDV from: (a) bare

lithium niobate; (b) Phononic

bandgap structure; and

cavities with (c) D = 0.75a = 15

μm, and (d) D = 1.0a = 20 μm.

The lattice period a is 20 µm.

Figure 4. Maps of the displacement of

surface phonons |U| in the x-y plane

(upper panels) and along the white

dashed line of the cavity (lower

panels) measured using the LDV on a

cavity with a defect of D = 20 μm at

the three different locations, (a)

inside the bandgap (vii), (b) at the

cavity resonance (v), and, (c) at the

edge resonance (vi).


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The measured spectral responses of the surface phonon displacement |U| are presented in Figures 3a-d for samples 1-4, respectively. Figure 3a presents the response from the blank sample, revealing the SAW bandwidth of the fabricated IDT. Figure 3b clearly indicates the existence of a surface phononic bandgap as expected. In particular, the existence of surface cavity resonances on cavity samples (samples 3 and 4) is well confirmed by the experiment, indicated by the peaks observed inside the bandgap as presented in Figures 3c and 3d for D = 0.75a = 15 µm and D = 1.0a = 20 µm, respectively. In addition, we observe two peaks within the bandgap for D = 0.75a in Figure 3c that agrees well with the simulation, thus confirming the interaction between the upper edge and surface cavity resonances previously discussed. Overall experimental results presented in Figures 3a-c appear to be in a good agreement with the simulation results in Figure 2a.

To gain insights into the observed resonances, we excite the cavity of D = 1.0a = 20 µm at three different frequencies, corresponding to the peaks at v, and vi, and also at vii in the gap in Figure 3d. For each frequency, we perform LDV area scans along the cavity parallel to the x axis to map the surface phonon displacement |U|. The measured displacements |U| are presented in Figures 4a-c for locations vii, v, and vi, respectively, in good agreement with the calculation.

Figure 5. Phonon-Polariton Entrapment in Homogenous Surface Phonon

Cavities, indicated by the simultaneous localization of both surface phonons

and

The LDV results in Figure 4, nevertheless, comprise only measurements of the displacement amplitude |U| at the substrate surface. It would also be valuable to analyze the characteristics of the surface cavity resonance beneath the substrate of the cavity to qualitatively determine the quality of the resonance along with the accompanying electric fields |E| induced by the phonon-polariton coupling. Figure 5 clearly shows the

confinement of the displacement associated with the cavity resonance within a wavelength beneath the surface, evanescently extending into the substrate where coupling with the bulk radiation from the cavity is insignificant. Additionally, it can be seen from that the accompanying electric field |E| is simultaneously localized within the defect area due to the phonon-polariton bandgap.

In summary, we have presented the first univocal observation of the entrapment of phonon-polariton in homogenous surface phonon cavities. The cavity is based on a phonon-polariton coupling within a bandgap structure that arises from periodic domain inversion on a single crystal piezoelectric lithium niobate with a defect of a single domain. In addition to demonstrating that the observed resonances are non-radiative and decoupled to bulk radiation, which is critical for high Q cavities, we also show the possibility to tune the surface cavity resonance spectra simply by varying the defect width. Such an ability to excite surface cavity resonance that is non-radiative with simultaneous localization of the electric field together with the advantage of a cavity that is physically formed from a completely monolithic and uniform material offers unique opportunities for widespread applications for example in actuation, detection, and phonon lasing that can be fully integrated with other physical systems such as quantum acoustics, photonics, and microfluidics.

[1] D. Yudistira, A. Boes, B. Djafari-Rouhani, Y. Pennec, L. Yeo, A. Mitchell, J. Friend, Phys. Rev. Lett. 2014, 113, 215503.

[2] D. Yudistira, A. Boes, A. R. Rezk, L. Y. Yeo, J. R. Friend, A. Mitchell, Adv. Mater. Interfaces 2014, 1.

[3] D. Yudistira, A. Boes, D. Janner, V. Pruneri, J Friend, A. Mitchell, J. Appl. Phys. 2013, 114, 0549

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