Design of Channel Filter based on Asymmetric One-Dimensional Defective Photonic Crystal for Broadband Responses

Transcription

1 Proceeding of the Internationa uticonference of Engineer and Computer Scientit 25 Vo II, IECS 25, arch 8-2, 25, Hong Kong Deign of Channe Fiter baed on Aymmetric One-Dimeniona Defective Photonic Cryta for Broadband Repone Amar Aming and Ratchapak Chitaree Abtract A tudy of the aymmetric geometry baed on a one-dimeniona defective photonic cryta i reported. A common tructure in the form of (HL) 4 L(HL) 4 i numericay invetigated to be uitabe for channe fiter with broadband repone. The tranmiion characteritic, anayed by the Tranfer atrix ethod (T), of the propoed tructure in UV, VIS and IR range are ceary iutrated. A number of intereting feature on the defect mode uch a tranmittance eve, fitering frequency and the number of mode are oberved when the defect ayer thickne i adjuted. The reut how a promiing potentia of the deigned channe fiter for variou appication incuding the optica communication. Index Term One-dimeniona defective photonic cryta, Aymmetric photonic cryta, channe fiter, Tranfer atrix ethod (T), defect mode I. INTRODUCTION Optica fiter i a device for eectivey tranmitting ight in a particuar range of waveength whie the other i bocked. It widepread ue are found in variou area of interet uch a nanotechnoogy [-2], atronomy [3] and communication [4-7]. Deigning i the firt tep in making an effective channe fiter in many appication. Up to now, there are an increaing number of deigned and deveoped fiter to cover operating waveength from utravioet (UV) to terahertz (THz) waveength [4-4]. The one-dimeniona photonic cryta (D-PC) firt introduced by Yabonovitch [5] and Sanjeev [6] ha become a tructure of choice to deign a fiter with good characteritic. D-PC i an artificia ayered materia with periodicity of different refractive indice and thicknee [7]. D-PC can guide the fow of ight paing through it tructure. Principay, the exitence of the photonic band gap (PBG) in PC prohibit a certain waveength that fa within the PBG. Due to a impe tructure, D-PC i the bet candidate for a channe fiter deign with particuar anucript receiveecember 29, 24; revied January, 25. Thi work wa upported in part by Appied Optic reearch, Facuty of Science, ahido Univerity. Deign of Channe Fiter baed on Aymmetric One-Dimeniona Detective Photonic cryta for Broadband Repone. Amar Aming i a doctora tudent in Department of Phyic, Facuty of Science, ahido Univerity, Phayathai, Bangkok, Thaiand (correponding author to provide phone: ; e-mai: [email protected]). Ratchapak Chitaree i Profeor in Department of Phyic, Facuty of Science, ahido Univerity, Phayathai, Bangkok, Thaiand (e-mai: [email protected]). pecification. Different dieectric, meta, emiconductor and organic materia have been invetigated numericay to expore their potentia a D-PC baed bandpa fiter [8-22]. By a theoretica deign, D-PC ue the effect of interference to effectivey tranmit ight over a deirabe range of waveength. For exampe, a tranmiion fiter made of Si/SiO 2 photonic cryta wa numericay and experimentay hown to work in IR range [7]. The binary tructure on metaic-dieectric photonic cryta wa tudied and fabricated a a bandpa fiter to cover appication in UV range [4] and the deign of tranmiion band uing Ta 2 O 5 and SiO 2 photonic cryta wa ao deveoped to ue in the communication [5]. Note that, thee appication are reaized by uing pure PC tructure. For more controabe feature of D-PC baed channe fiter, the doping of ome materia into the pure PC, changing the thickne of the ayer or removing a ayer from it, caed defective PC ha been increaingy tudied. The ocaized or defect mode within the PBG correpond to the reonant tranmittance peak due to the change of the interference behavior of the ight [23]. The introduction of the defect in the deign of D-PC tructure ead to variou appication uch a pitter and optica fiter [2,24]. So far, the effort to extend for even more intereting appication i continuay tudied. In thi tudy, a common and impe deign for channe fiter i propoed baed on the defective PC. A nove narrow band-pa fiter at norma incidence over broadband range are deigned and numericay invetigated through Tranfer atrix ethod (T). Baed on a common tructura configuration of (HL) 4 L((HL) 4 deign in which a defect ayer i introduced into a periodic ayered tructure, a defect mode i found to appear at deired waveength in utravioet (UV), viibe (VIS) and near infrared (IR) range. The deigned fiter a a channe fiter exhibit a high tranmiion performance, harp edge and good rejection of the undeired ideband. By jut changing the combination of materia baed on the deigned tructure, the operating waveength of a channe fiter can be tuned convenienty to cover the range of waveength in UV, VIS and IR. The propertie of the propoed channe fiter in term of tranmiion and bandwidth are ao invetigated in thi tudy. ISBN: ISSN: (Print); ISSN: (Onine) IECS 25

2 Proceeding of the Internationa uticonference of Engineer and Computer Scientit 25 Vo II, IECS 25, arch 8-2, 25, Hong Kong II. ATHEATICAL ODELLING A. Tranfer atrix ethod (T) [7] A numerica method o caed Tranfer atrix ethod (T) i widey ued to ove the ampitude of the ight propagating inide D-PC. Conider a genera defective photonic cryta tructure, air/(hl) m D(HL) m /air, in which H repreent the ayer of high refractive index and L repreent ow refractive index materia an i the defect ayer. Fig. One-dimeniona photonic cryta (D-PC) with defect To compute the defect mode in the tranmiion pectrum, T for the ytem can be written a A A = 2 N B 2 22 BN = = D ( ) ( ) D 2 m m y H L D H L 2 22 Where and m i the number of ayer and = DPD tand for H, L an ayer. For TE wave For T wave D = n coθ n coθ coθ coθ D = n n θ i the ray ange in the ayer. Ao, the propagation matrix can be defined a iδ e P = iδ e 2π d ; δ = n coθ λ B. and Refectance [7] Uing T method, the tranmittance and refectance of pane wave through a periodic ayered tructure, the incident ight from medium, the refection r and tranmiion t coefficient are B r = A B = P A t = Uing the matrix equation Refectance R i given by A B = r = t = R = r = Providing that the medium i oe. T i given by n θ n θ T = t = n coθ n coθ co 2 co III. RESULT AND DISCUSSION A defect ayer in aymmetric geometry with a common tructure of air/(hl) 4 L(HL) 4 /air are tudied a channe fiter to cover UV, VIS and IR region. The propoed configuration of channe fiter conit of a defect ayer (with a refractive index of n D ) inerted into aternating ayer of high (n H ) and ow (n L ) refractive index materia a hown in Fig.. Note that a defect mode referred in the tranmittance characteritic correpond to a deign waveength (λ ) for a channe fiter. Each optica width of the ayer i choen to be a quarter-waveength, i.e., n H d H = n L d L = n D = λ /4. The number of periodicity i optimized for N = 4. The ubtrate i air. Thi propoed fiter wa deigned and cacuated through tranfer matrix method (T) ony at norma incidence over UV, VIS and IR range. The tranmiion performance of the channe fiter at each range of waveength in term of high tranmittance, tunabe bandpa, photonic band gap (PBG) and band edge are invetigated and dicued Fig. 2. Tranmiion pectrum of deigned fiter in UV range. 2 ISBN: ISSN: (Print); ISSN: (Onine) IECS 25

3 Proceeding of the Internationa uticonference of Engineer and Computer Scientit 25 Vo II, IECS 25, arch 8-2, 25, Hong Kong A. Deign of Utravioet (UV) fiter Baed on the aymmetric PC tructure, air/(hl) 4 D(HL) 4 /air, the propoed channe fiter in UV range i eected a the ayer of two different materia TiO 2 (n H = 2.8) and gf 2 (n L =.4). A defect ayer of gf 2 (n D =.4) i introduced into PC tructure. With each ayer of quarter-waveength thickne, the propoed tructure, (TiO 2 /gf 2 ) 4 gf 2 (TiO 2 /gf 2 ) 4, i cacuated at the deign waveength λ = 3. The deigned PBG i cacuated to be between 24-4 and the defect mode ocate at the deign waveength within the UV range. Fig 2. how the tranmiion pectrum of the deigned fiter. To achieve a maximum intenity of the defect mode, it i recommended to eect a high contrat of the refractive index materia. Refractive index of the defect ayer i choen to coe to the ow refractive index materia o a to maximize the tranmittance of the defect mode. In thi tudy, gf 2 i a uitabe materia for thi purpoe becaue of it ow aborption in the UV range. In addition, the propoed channe fiter can be tuned to a deired waveength by changing the thickne of the defect ayer. The poition of defect mode i hifted to a onger waveength a the thickne of defect ayer increae. On the contrary, the decreae of the defect ayer thickne caue to ower the deigned waveength. The reation i ceary hown in Fig. 3. The periodicity of the tructure, N = 4, give rie to a harp edge and high tranmiion. Athough the increae of the periodicity ha infuenced on harp edge, thi inevitaby caue the decreae of the tranmittance eve of UV channe fiter = 35 = λ = 75 = Fig. 3. Tranmiion pectra of deigned fiter baed on aymmetric defective PC of air/(tio 2/gF 2) 4 gf 2 (TiO 2/gF 2) 4 /air at norma incidence in UV range. Bandpa Waveength () Thickne of defect ayer () Fig. 4. The variation of channe waveength of a inge defect mode with different thicknee of defect ayer baed on aymmetric defective PC of air/(tio 2/gF 2) 4 gf 2 (TiO 2/gF 2) 4 /air at norma incidence in UV range. The imuation reut how that the thickne change of the defect ayer ignificanty affect a pectra tranmiion of the propoed UV fiter. Two defect mode apparenty occur when the defect ayer width ha been changed twice a thick a an origina vaue. A defect mode near the band edge of the ong waveength finay diappear if the thickne keep increaing. However, thi ceary point out that the channe fiter baed on the propoed tructure can work a either a inge or muti-channe operation depending on the adjutment of the defect ayer thickne Fig. 5. Tranmiion pectrum of a deigned fiter in a viibe range. B. Deign of Viibe (VIS) fiter Aymmetric one-dimeniona defective photonic cryta tructure baed on air/(hl) 4 D(HL) 4 /air i ao ued for a channe fiter in the viibe range. H i taken to be Ti (n H = 2.7) and L i taken to be A (n L =.2). To achieve a high tranmiion, a defect ayer i choen to be a ow refractive index materia of A (n D =.2). So, the deigned fiter i (Ti/A) 4 A(Ti/A) 4. Each ayer thickne i et to be a quarterwaveength. For norma incidence, the reut how that the PBG i 4 7 and the defect mode ocate at a deign waveength, λ = 5 (Fig. 5) = 6 = λ = 5 = Fig. 6. Tranmiion pectra of deigned fiter baed on aymmetric defective PC of air/(ti/a) 4 A(Ti/A) 4 /air at norma incidence in viibe range. Fig. 6 ceary how that by increaing the thickne of defect ayer the channe i hifted toward the onger waveength, wherea the hift to the horter waveength occur a the thickne decreae. The increae of the periodicity i again found to decreae the tranmiion of the deign waveength. Therefore, the periodicity of N = 4 i the ISBN: ISSN: (Print); ISSN: (Onine) IECS 25

4 Proceeding of the Internationa uticonference of Engineer and Computer Scientit 25 Vo II, IECS 25, arch 8-2, 25, Hong Kong optimum condition for the performance of the channe fiter. From Fig. 6, the reut how that two defect mode are found within the PBG if the width of defect ayer i twice a thick a the origina quarter-waveength. One of the two defect mode whoe poition near the band edge of the ong waveength diappear according to the increment of the thickne of defect ayer. Thi iutrate that the variation of defect ayer thickne can be ued to obtain either a inge channe fiter or muti-channe fiter. Bandpa Waveength () Thickne of defect ayer () Fig 7. The variation of channe waveength of a inge defect mode with different thicknee of defect ayer baed on aymmetric defective PC of air/(ti/a) 4 A(Ti/A) 4 /air at norma incidence in viibe range. C. Deign of Infrared (IR) fiter IR bandpa fiter i again deigned with aymmetric geometry of air/(hl) 4 D(HL) 4 /air where H i GaA (n H = 3.4), L i LiF (n L =.36) an i LiF (n D =.36). The deign waveength wa choen to be λ = 6. The tranmittance of the deigned fiter, (GaA/LiF) 4 LiF(GaA/LiF) 4, at norma incidence how that a high tranmittance of the defect mode can be achieved when it refractive index i coe to the ow refractive index materia Waveength(µm) periodicity N = 4. Thi deign waveength i eected for near-infrared appication uch a medica diagnotic, food quaity contro and optica communication = 2 = λ = 28 = Fig. 9. Tranmiion pectra of deigned fiter baed on aymmetric defective PC of air/(gaa/lif) 4 LiF(GaA/LiF) 4 /air at norma incidence in infrared range. Bandpa Waveength () Thickne of defect ayer () Fig. The variation of channe waveength of a inge defect mode with different thicknee of defect ayer baed on aymmetric defective PC of air/(gaa/lif) 4 LiF(GaA/LiF) 4 /air at norma incidence in infrared range. By increaing the width of the defect ayer twice a thick a it origina quarter-waveength, two defect mode are oberved within the PBG. When the thickne of defect ayer increae, the firt defect mode i hifted toward the onger waveength. The defect mode diappear whie the other defect mode near hort waveength remain. By varying the thickne of the defect ayer, a deign waveength can be achieved. Therefore, thi deigned tructure how it function a a inge or muti-channe fiter, peciay appied in DWD appication. Note that the 3 and 55 are covered in thi propoed tructure. Fig. 8. Tranmiion pectrum of deigned fiter in infrared range. There i a defect mode introduced within the PBG which i 8-6. A defect mode i hifted to the onger waveength for increaing of the defect ayer thickne. In contrat, the defect mode i hifted to the horter waveength with decreaing of the thickne of defect ayer. The defect mode become weak or even diappear if the periodicity i greater than 4. So, the enhancement of the high tranmittance for the deigned fiter i atified with the ISBN: ISSN: (Print); ISSN: (Onine) IV. CONCLUSION Uing the Tranfer matrix method (T), a narrow channe fiter can be deigned baed on aymmetric defective photonic cryta (PC) of air/(hl) 4 L(HL) 4 /air. With the combination of appropriate materia and a quarterwaveength width of the defect ayer, a inge defect mode occur within the PBG at the deign waveength, within the utravioet (UV), viibe (VIS) and infrared (IR) range. The poition of defect mode can be hifted toward a onger waveength a the defect ayer thickne increae. The twice IECS 25

5 Proceeding of the Internationa uticonference of Engineer and Computer Scientit 25 Vo II, IECS 25, arch 8-2, 25, Hong Kong increment of the defect ayer thickne with repect to the quarter-waveength defect ayer thickne ead to the introduction of two defect mode inide the PBG. The optimum periodicity, N = 4 in thi tudy, numericay iutrate a high tranmiion of defect mode and harp edge of the pectrum. Such deigned fiter i fuy fexibe to contro the defect mode by changing the width of defect ayer. The preence of either a inge or two defect mode i utiized to deign a inge or muti-channe fiter for variou appication incuding the optica communication. Tabe how the ummary of channe fiter for UV, VIS and IR range baed on the propoed aymmetric geometry tructure, air/(hl) 4 L(HL) 4 /air. Range of waveength () TABLE I SUARY OF THE DESIGNED FILTER Photonic band gap (PBG) () The combination of materia baed on air/(hl) 4 L(HL) 4 /air. Utravioet 24 7 (TiO 2/gF 2) 4 gf 2(TiO 2/gF) 2 4 Viibe 4-7 (Ti/A) 4 A(Ti/A) 4 Infrared 8-6 (GaA/LiF) 4 LiF(GaA/LiF) REFERENCES [] A.D.a. et.a, Study of the omnidirectiona photonic bandgap for dieectric mirror baed on porou iicon: effect of optica and phyica thickne, Nanocae Reaearch Letter, vo. 7, no. 39, 22. [2] P.S.N.a. et.a, Refractive Index Senor Baed on a D Photonic Cryta in a icrofuidic Channe, Senor, vo., 2, pp [3] R.I.B.a. et.a, Deign and deveopment of a highy efficient, utranarrowband optica fiter for ue in atronomica appication, Book Deign and deveopment of a highy efficient, utra-narrowband optica fiter for ue in atronomica appication, Serie Deign and deveopment of a highy efficient, utra-narrowband optica fiter for ue in atronomica appication, ed., Editor ed.^ed., 23, pp. [4] S.G.a. et.a, NarrowbanWD fiter baed on FIbonacci-ca quai-periodic tructure, Optic expre, vo. 5, no. 7, 27. [5].J.K. Hwekyung KI, Deign and Characterization of Dua-Band- Pa Fiter for Optica Communication, Journa of the Korean Phyica Society, vo. 53, no. 3, September, 28, pp [6].A.G.a.H.A.B. Reza Khodadadi, Adjutabe Fiter For Optica Communication Sytem Baed On One-dimeniona Photonic Cryta Structure, Internationa Journa of Engineering Reearch and Appication (IJERA), vo. 2, no. 6, November-December 22, pp [7] H..a.T.Y. Hyun-Yong Lee, Si-baed omnidirectiona refector and tranmiion fiter optimized at a waveength of.55 μm, Appied phyic etter, vo. 8, no. 24, 22. [8] H.N.a. et.a, Highy tunabe photonic cryta fiter for the terahertz range, Optic Letter, vo. 3, no. 5, 25. [9] J.H.a. et.a, Narrow bandpa tunabe terahertz fiter baed on photonic cryta cavity, Optica Society of America, vo. 5, no. 6, 22. [] J.H.a. et.a, Narrow bandpa tunabe terahertz fiter baed on photonic cryta cavity, Optica Society of America, vo. 5, no. 6, 22. [] J. Li, Terahertz wave narrow bandpa fiter baed on photonic cryta, Optic Communication, vo. 283, 2, pp [2] J.-S. Li, Terahertz wave omnidirectiona dieectric mirror, Optic & Laer Technoogy, vo. 43, 2, pp [3] C.-J.W.a.H.-C. Lin, Invetigation of Photonic Band Gap in a Semiconductor-Organic Photonic Cryta in Utraviet Region, Optica Review, vo. 8, no. 4, 2, pp [4]..a..S. Zoran Jakic, Siver-iica tranparent meta tructure a bandpa fiter for the utravioet range, Jouna of Opitc A: Pure and Appied Optic, vo. 7, 25, pp [5] E. Yabonovitch, Inhibited Spontaneou Emiion in Soid-State Phyic and Eectronic, Phyica Review Letter, vo. 58, no. 2, 987. [6] S. John, Stong Locaization of Photon in Certain Diordered Dieectric Superattice, Phyica Review Letter, vo. 58, no. 23, 987. [7] P. Yeh, Optic of Periodic Layered edia, Optica wave in Layered edia, Wiey Intercience, 988. [8].J.B..Scoora, A.S. Pethe, J.P. Dowing, C.. Bowden and A.S. anka, Tranparent, mettao-dieectric, one-dimeniona, photonic band-gap tructure, Journa of Appied Phyic, vo. 83, no. 5, 998, pp [9] S.K.A.a. et.a, Deign of a tunabe optica fiter by uing a onedimeniona ternary photonic band gap materia, Progre In Eectromagnetic Reearch, PIER, vo. 4, 28, pp [2]..a..S. Zoran Jakic, Siver-iica tranparent meta tructure a bandpa fiter for the utravioet range, Jouna of Opitc A: Pure and Appied Optic, vo. 7, 25, pp [2].I.a.E.A.-R. Arafa H. Ay, Comparative Study of the One Dimeniona Dieectric and etaic Photonic Cryta, Optic and Photonic Journa, vo. 2, 22, pp [22] X.-f.X.a.J.-y. Ding, A wide band-pa fiter of broad ange incidence baed on one-dimeniona metao-dieectric ternary photonic cryta, Opt Quant Eectron, vo. 4, 29, pp [23] G.Guida, An Introduction to photonic band gap (PBG) materia, Progre In Eectromagnetic Reearch, PIER, vo. 4, 23, pp [24] A.K.a. et.a, Wide Range Temperature Senor Baed on One- Dimeniona Photonic Cryta with a Singe Defect, Internationa Journa of icrowave Science and Technoogy, vo. 22, Artice ID 82793, 22. [25] R.K. Sanjeev Sharma, Kh.S. Singh, Vipin Kumar aneepti Jain, Deign of a tranmiion T mode fiter uing one-dimeniona ternary photonic cryta, Proc. AIP Conference Proceeding, AIP Pubihing, 23. [26] V.K.a. et.a, Defect mode Propertie and Origin in one Demeniona Photonic Cryta, Photonic and Optoeectronic vo. 2, no., 23. [27] R.S.a. et.a, Deign of photonic band gap fiter, Progre In Eectromagnetic Reearch, PIER, vo. 8, 28, pp ISBN: ISSN: (Print); ISSN: (Onine) IECS 25