TWI289214B - Chiral photonic and multi-wavelength chiral photonic filter - Google Patents

Abstract

The present invention relates to a chiral photonic structure, comprising a first portion and a second portion. The first portion has a plurality of first pitches that vary continuously. The second portion is connected to the first portion and forms a defect plane therebetween. The second portion has a plurality of second pitches that vary continuously. The first pitch of the first portion next to the defect plane is different from the second pitch of the second portion next to the defect plane. Therefore, the variation of the pitch on the defect plane is discontinuous.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral photonic crystal and a filter including the same, relating to a spiral photonic crystal with discontinuous pitch variation and including the same A filter for a spiral photonic crystal. [Prior Art] An optical filter is an important component in an optical transmission system for screening a narrowband band such that the spectral components of this band pass or are prohibited from passing. General Light > The operating principle of the filter is to use physical methods such as interference or diffraction, and the filtered band can be fixed or adjustable, such as Fabry-Bilo interference. Instrument, Bragg fiber grating, dielectric film Interference filters, Mach-Zehnder filters, diffraction grating filters, etc., see [R.

Ramaswami and K. N. Sivarajan, Optical Networks: A Practical Perspective, Morgan Kaufmann, San Francisco, pp. 90-119 (1998)]. However, these optical filters are not capable of generating a multi-wavelength wave-wave mechanism in the inline transmission direction. The Fabry-Below-interference device must have an incident angle to generate multi-beam interference. See [DY Hsu? JW Lin] , and SY Shaw, fWide-range tunable Fabry-Perot array filter for wavelength-division multiplexing applications/ Applied Optics 44 (9), 1529 (2005)], the diffraction grating filter must be decomposed at different diffraction angles For signals of different wavelengths of light, see [ML C. Parker, A. D. Cohen, and R. JL Mears, 'Dynamic Digital Holographic Wavelength Filtering/ J. Lightwave Technol. 16 (7), 1259 (1998)], thin 105056 .doc 1289214

Membrane interference filters can only reflect or penetrate specific single-wavelength signals, see [Y. Inoue? T. Oguchi, Υ·Hibino, S. Suzuki, M. Yanagisawa, K. Moriwaki, Y. Yamada, Tilter-embedded wavelength -division multiplexer for hybrid-integrated transceiver based on silica-based PLC, ' Electron. Lett 32, 847 (1996)], Mach-Zehnder filter must add another optical path to cause phase delay to produce specific wavelength interference For effects, see [Μ·H· Shih, W. J. Kim, Wan Kuang. JR Cao? H. Yukawa, SJ Choi, JD ΟΈτίβη, PD Dapkus, and WK Marshall, 'Two-dimensional photonic crystal Mach-Zehnder interferometers/ Appl. Phys. Lett 84, 460 (2004)]. For the one-dimensional photonic crystal design filter, see [I·D. Villar, I·R· Matias, and F. J. Arregui, nFiber-Optic Multiple-Wavelength Filter Based on One-Dimensional Photonic Bandgap Structures With Defects, 1* J. Lightwave Technol. 22(6), 1615 (2004)] and fiber grating, see [GP Agrawal and S. Radic? 1fPhase-Shift Fiber Bragg Gratings and their Application for Wavelength Demultiplexing, '' IEEE Photon· Technol. Lett· The principle of 6(8), 995 (1994)] is similar. The method used to generate multi-wavelength filtering is more complicated. It is necessary to deposit a dielectric film in a complicated structure, and attention should be paid to the arrangement of the positions of the respective resonant cavities. It is difficult to overcome the thickness control error of each dielectric layer and affect the resonant penetration wavelength position of the actual demand. Even if the cavity design can introduce liquid crystal as a tunable filter, see [I·D. Villar, IR Matias, FJ Arregui , and RO Claus, 105056.doc 1289214 ''Analysis of one-dimensional photonic band gap structures with a liquid crystal defect towards developme Nt of fiberoptic tunable wavelength filters, 11 Opt. Express 11(5), 430 (2003)], but the linear modulation range exhibited by the wavelength is limited. The cholesteric liquid crystal (CLC) structure has three main basic forms, in which a spiral structure in a planar form exhibits a special photonic band gap phenomenon of selective light scattering. When the direction of the optical rotation of the incident light coincides with the spiral direction of the cholesteric liquid crystal, the optical rotation of the specific wavelength band causes a reflection phenomenon, but if the optical rotation direction is opposite to the spiral direction, no reflection occurs. Optical filters are important components in optical transmission systems. For the optical transmission window of the optical fiber, the International Telecommunications Union (ITU) has standardized six transmission bands, namely O-Band (1260 nm~13 10 nm) and E_Battery (1360 nm~). 1460 nm), S-Band (1460 nm to 1530 nm), C-Band (1530 nm to 1565 nm), L_Band (1565 nm to 1625 nm), and U-Band (1 625 nm to 1675 nm) The ordinary light or extraordinary light refractive index of a typical liquid crystal is about 1.4 to 1.7, and the birefringence is about 0.1 to 0.2. The effect of nonlinear effects is often negligible (for example, absorption), and the ratio according to the Maxwell's equation. Scalability, by changing the maximum and minimum range of the cholesteric liquid crystal pitch gradient, the photonic bandgap (reflection band) can be moved to cover the communication wavelength range of 1260 nm to 167 nm, as described below. Referring to Figures la and lb, there are shown schematic diagrams of a spiral structure of a liquid crystal structure having a pitch gradient and a schematic diagram of a liquid crystal molecular guide axis arrangement. The liquid crystal molecules inside the cholesteric liquid crystal structure 1 are arranged in a planar spiral 105056.doc 1289214 structure, and the cholesteric liquid crystal structure 1 is composed of a plurality of layers, each layer having a -guide axis, and the d-guide axis is rotated along the helix axis u The directions of the guide axes between adjacent layers are different and continuously change, and the distance between two layers having the same guide axis direction is defined as a pitch by 2 times of the distance. The pitch systems are all different and continuously varying to form a pitch gradient. It is particularly important to note that this pitch gradient structure must stabilize its structure by a polymer monomer capable of generating a polymerization reaction in the constituent material. This polymerization reaction can be initiated by a temperature change or a photochemical reaction. The main parameters of the cholesteric liquid crystal junction W are: the extraordinary refractive index of the liquid crystal is %, the refractive index of the light is ~', the maximum pitch of the helical structure is I', the minimum pitch is Pmin, and the incident angle of the thickness h is Θ. The pitch gradient change can be exponentially described as follows: Household (4) = household minexp(|lnr) a where Γ — />_ /4. The dielectric tensor of cholesteric liquid crystal can be expressed as ^11 ^12 ^3^1 ', two €2\^22 ^23 1^31 ^32 ^33 J and the elements of the 丨 tensor are expressed as I under the coordinates ^ (1) (2) ~^i)c〇s|^~y2 2 -^i)s

Ana^yx(Z) / 4π, "Z)-five (5 + L)-bean q)cos z(2)= 6*丄^€2χ^ε ^ € = 〇=Generally, the square of the refractive index Similar to the media at the very high frequency, it can be expressed by the following formula: 105056.doc (3) ^111289214 Detailed mathematical theory simulation by the Maxwell square of electromagnetic waves - (Ex) (E, 0 Ey =^oQ( ^) E • & Hx y Hx HVi ^〇0(^)ψ = δ(ζ)ψ where (4) 裎式出(5) Q(^) = 〇〇S2\ 1 -- - Ίο -£il Vo 0 0 \2 k〇—1 € 22 k' \Λ

A.£ll Vo 0 0 J *33 0 0 0 and ~ is the essential impedance of free space, and is the self-densation of the square J of the medium in the χ direction, and the Herm Hertz equation can be obtained. nK^^EJ+^E==0 where 0 is in this sense, 丨+heart)/2 and & 睥, 4^)/2, when the spiral f; left-handed, i. Referring to Figure 2, the display has a thread penetration wrinkle. Ffl 2# spleen Ί 梯度 之 之 梯度 梯度 梯度 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图 图Taking the cholesteric liquid crystal of dextro 105056.doc -10- 1289214 as an example, the design of the penetrating spectrum is set to 非 寻 光 . . . . . . . . . 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常 寻常The maximum pitch is set to = 92 〇 nm, and the minimum pitch is 4 = outline nm. The photonic band gap shown in Figure 2 is in the oblique region of wavelength 1255 nm~1665 nm • where the right-handed light (RCP) has a reflection band and left-handed light (LCP) does not exist. The filter using the cholesteric liquid crystal structure 会 has a circular polarization selective filtering effect, and the cholesteric liquid crystal structure i φ has a wider reflection frequency than the equal pitch structure due to the pitch gradient. However, the cholesteric liquid crystal Structure i does not have the function of multi-wavelength chopping. Therefore, it is necessary to provide an innovative and progressive spiral photonic crystal and a chopper including the spiral photonic crystal to solve the above problems. SUMMARY OF THE INVENTION The object of the present invention is to provide a helical photonic crystal comprising: a 2-part and a second part. The first portion has a plurality of different first pitches. The first pitches are continuously varying. The second portion of the tray is connected to the portion, and the first portion forms a two defect plane with the second portion. The second portion has a plurality of different second pitches. The second pitch is a continuous change, wherein the first pitch is connected to the defect plane, and the first pitch is different from the second pitch of the second portion connected to the defect plane and formed on the defect plane The pitch changes are not continuous. By this, the effect of coaxial or non-coaxial filtering can be realized, and the effect of multi-wavelength filtering can be achieved by simple construction, and can be used for a chopper of a wavelength multiplexer or the like. In addition, the components do not need to be applied by external electromagnetic fields or force fields. 105056.doc 1289214 The design of the light-wave or wave-band is easy to adjust the error that may occur during the manufacturing process. Another object of the month is to provide a filter comprising a first spiral photonic crystal and a one-half wavelength far-helical photonic crystal comprising a first portion having a plurality of different first portions The first snail, such as the first pitch and the first pitch, is continuously servant.钕垓 钕垓 钕垓 一 一 螺 ^ ^ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ The second pitch system is continuously variable. The first pitch system connected to the first defect plane is different from the second portion connected to the first defect plane: The pitch variation on the first-defect plane is discontinuous. The first spiral photon crystal package contains a smash and a fourth part. The second κ has a plurality of different continuous changes. The fourth part of the Weipan today's first / Hai 4 brother two pitch system is connected to the second part of your Xing 6 Hai, part of which is formed with the fourth part - the first ^ - seventy 2 釈丨曰 十面, the fourth portion and the fourth pitch, the fourth pitch is continuously changed, wherein the third portion is connected to the fourth defect plane and the fourth Part of the connection is in the second,,, and not as good as the fourth pitch of the ton ton 曰 曰 曰 曰 曰 , , , , , , , , 缺陷 缺陷 一 一 一 一 第四 第四 第四 第四 第四The ::: one wavelength chip is sandwiched between the first spiral photonic crystal and the second spiral photonic crystal. [Embodiment] Referring to Figures 3a and 3b, respectively, the spiral photonic crystal 105056.doc of the first embodiment of the present invention is shown. 12· 1289214 Schematic diagram and schematic diagram of the arrangement of the liquid crystal molecular guide axes. In the case of the steroidal liquid crystal structure, the spiral light dipole of the present invention is illustrated: and it is understood that the spiral photonic crystal does not Cholesterol: 2: Limit. The cholesteric liquid crystal structure 2 can be used as - 遽 口 口 / /, including a first part 21 and a second part 22 - Part 21 is composed of a plurality of first a layer (not shown), each having a - lead-guide axis, the first guide shaft rotating along a first screw axis 23, to be adjacent to the first guide between the first layers The direction of the glaze is different and is connected/parental, and the two have the same direction of the first guiding axis, and the distance of 2 times of the distance is defined as the distance of the s of the snail ± ^ is the brother-pitch. The first-pitch systems are all continually changing, and the change between the first snails is a first snail gradient. Further, the first portion of the second end surface 212 ^1 has an end surface 2U and a first portion 2', and the first end surface 211 is perpendicular to the first spiral shaft 23 and receives the light 24. In the usual case, the first portion 21 can be regarded as a above-mentioned cholesteric liquid crystal junction, and the relevant theoretical formula. The second portion 22 of the sterol liquid crystal structure is composed of a plurality of second layers (not shown). Each of the layers has a second guide axis. The second guide axes are along a second spiral. = 疋 ' 'the direction of the second guide axis between adjacent second layers is different and is connected... The distance between the second layers having the same second guide axis direction is defined as the second pitch by 2 times the distance . The second pitch systems are all identical and continuously varying, and the change between the second pitches is a second pitch. In addition, the second portion 22 has a third end face 221 and a fourth face 222 'the portion of the incident light 24 is emitted by the fourth end face 222 105056.doc -13-1288914, the other portion The incident light 24 is reflected by the first end surface 211. The third end surface 221 of the second portion 22 is connected to the second end surface 212 of the first portion 21, and a defect plane 26 is formed between the first portion 21 and the second portion 22. In the usual case, the second portion can be regarded as one of the above-mentioned cholesteric liquid crystal structures i, and the relevant theoretical formula of the cholesteric liquid crystal structure 1 is applied. Preferably, the second portion 22 is identical to the first portion 2, that is, the two materials are the same, and the first spiral gradient is equal to the second spiral gradient, and the second spiral axis 25 is equal to The first screw shaft 23. The thickness of the first portion 22 is the same as the thickness of the first portion 21, which is d 〇. In this embodiment, the first pitch of the first portion 21 connected to the defect plane 26 is different from the first pitch. The second portion 22 is connected to the first pitch ' on the defect plane % and forms a pitch variation discontinuity on the defect plane 26. That is, the first portion 21 and the second portion 22 have a phch jump, and the spiral changes immediately adjacent to the defect plane 26 are continuous, but are discontinuous in the pitch variation. Referring to Fig. 4, there is shown a transmission frequency 4' of a spiral photonic crystal of the first embodiment of the present invention, wherein 2d = 2〇Jpmin. Figure 4 is a graph showing the total thickness of the cholesteric liquid crystal structure 2 of Figure 3a as 2c / = 2 〇 Pmin, and the chromosomal liquid crystal of the right-handed structure as an example. The design parameter is set to an extraordinary refractive index. % =1·65 and the ordinary light refractive index 〜=1·5, the maximum pitch of the first portion 21 and the second portion 22 are both set to 1=92 〇 nm, and the minimum pitch is set to 4=8 〇〇 nm. As can be seen from Figure 4, the left-handed light (LCP) will penetrate completely, but in the photonic band gap (that is, in the region of wavelength 1255 nm ~ 1665 nm), the right 105056.doc 14 1289214 optical rotation (RCP) will A plurality of specific penetration wavelengths form a plurality of defect modes. In the present invention, the effects of the defect modes are used as filtering functions. The time delay due to the filter's unavoidable phase distortion on the signal, 'ie Group Delay', is shown at the top of Figure 4. Comparing the group $delay with the defect modes, it can be found that the narrower the bandwidth of the normal defect mode, the more severe the phase distortion will be, that is, the time delay will be longer. • Since the position of each defect mode is different in the photonic band gap, the depth of the band gap is different. Generally, the closer the depth of the defect t is to the center of the photonic band gap, the deeper the phase is. The stronger the restraining effect of the photon of the corresponding wavelength by the photon energy, the more the number of resonances that continuously oscillate back and forth inside, and the longer the signal delays in time. In all the missing boards in Figure 4, the center wavelength of the defect mode with Ful1 Width at Half Maximum (FWHM) (about 4 nm) is 1435 (10), which corresponds to the most, the delay time is about 372. Fs. In addition, the illustration in the upper right corner of Fig. 4 shows that _ τ Θ has the smallest: the attenuation of the channel impedance of the FWHM defect mode is only about 丨〇 dB, and the attenuation is not large. Referring to Fig. 5', the transmission spectrum of the spiral photonic crystal of the first embodiment of the present invention is shown, which is 一, =, 〇, Pmin. As can be seen from FIG. 5, when the thickness of the cholesteric liquid crystal structure is increased to 2 "40 Pmin, the defect modes in the photonic band gap: the wood degree will be deepened by Ik", and a filtering effect of a narrower bandwidth can be produced. The number of simultaneous/equal missing modes also increases, and the distance between the defective modes also changes. In all the defect modes of the figure, the defect mode with the minimum full width at half maximum (FWHM) (about 0·6 nm) is added. The center wavelength is 1375, which is 105056.doc -15-1282914 in the upper right of Figure $. The channel block distance shown by the illustration is 3 nm at a center wavelength of 3 nm, which is greater than the attenuation of Figure 4. Although the filtered bandwidth can be reduced as the total thickness of the cholesteric liquid crystal structure 2 increases, the group velocity delay of the signal is added to the maximum of about 3417 fs. Therefore, the cholesteric liquid crystal structure 2 and other active components are When integrating, it is necessary to pay attention to whether the response speed of the system will decrease due to the increase of the group speed delay of the signal. Refer to Fig. 6' to show the relationship between the cholesteric liquid crystal structure with different total thickness and the wavelength in each missing mode. Defect mode is right The incident h' and the thickness of its abscissa are the total thickness (four) divided by the minimum pitch (Pmin). As can be seen from the figure, the number of defective modes increases with the total thickness of the cholesteric liquid crystal structure, and in addition to gradually increasing In addition, the center wavelength of the defect modes will gradually shift from the long wavelength to the short wavelength. The tendency of the appearance and position change of the defect mode at each central wavelength position can be expressed by the following equation: ^+i \ 2nAd cos0 = 1 ' ( 10) where "-=V^n, vn.., ^, and human> person +1, △ especially the refractive index matching layer thickness', the penetration mode of the defect mode is similar to the Fabry-Bilo interferometer The results are described as 'however, the reason for the multi-defect mode in the spectrum and the special sequence produced by the non-monochromatic interference of the Fabribi-Biro is different. The cause of the difference is different. The general Fabri-Bilo interference The wave direction component that needs to be obliquely is reflected by the mirror back and forth, and the interference sequence can be generated under a certain phase difference; however, the multi-defect mode appearing in the present invention is caused by the photonic band gap phenomenon. Resonance effect of multiple optical resonant cavity Moreover, it is related to the near-vertical wave vector component. This multi-modal vibration 105056.doc 16 1289214 architecture is shown in Figures 3a and 3b ^ 'The pitch gradient structure is regarded as being stacked with a different acoustic equivalent (8) cholesteric liquid crystal film In the "difference plane 26 on both sides of the gap, there will be the same equivalent pitch cholesteric liquid crystal film in pairs, forming a pair of cholesteric liquid crystal mirror cavity structure, and each pair of mirrors The cholesteric liquid crystal layer can be regarded as an index matching layer. In addition, the condition of forming a resonance wavelength for each cavity is not limited.

The resonance length of the cavity should also be matched with the photonic band gap band corresponding to the local cholesteric liquid crystal mirror, ie «II «J. (11) where; I. = W. Furthermore, the wavelength difference between the defect modes can define a free spectral range (FSR) as follows: 2nAdv (12) where 4 and Δ&lt;&lt;Δ々&lt;···<Δ&lt;. Equations (10) and (12) can be used as specifications for designing filters.

Referring to Fig. 7a, there is shown a permeation spectrum of a cholesteric liquid crystal structure according to a first embodiment of the present invention, wherein M = . Referring to Figure 7b, there is shown a transmission spectrum of a cholesteric liquid crystal structure of the first embodiment of the present invention, wherein M = 45 Pmin. 7 &amp; and 7b, the total thickness of the cholesteric liquid crystal structure 2 is ^ = 154 and 2^ = 45 / ^, and the penetration of all the defective modes can reach 100%. Referring to Fig. 8, there is shown a penetration spectrum 'where 2d := 25Pmin in the case of different incident angles of incident light in the cholesteric liquid crystal structure of the first embodiment of the present invention. It can be seen from Fig. 8 that when the incident angle 0 of the light becomes larger, the incident angle 105056.doc -17-1282914 Θ exceeds 20, except that the photonic band gap and the corresponding defect mode are shifted to the short wavelength position. . At this time, the attenuation of the defect mode penetration is generated, so when using the biliary liquid crystal structure 2 as a filter, it is necessary to pay attention to that the light incident angle is not excessively "about 0 to 20 degrees. Referring to Figures 9a and 9b, there is shown a schematic view of a spiral photonic crystal of a second embodiment of the present invention. In the present invention, the spiral photonic crystal of the present invention is illustrated by taking the cholesteric liquid crystal structure as an example, but it is understood that the spiral photonic crystal is not limited to the cholesteric liquid crystal structure. The biliary-positive structure 3 can be used as a chopper, including a first and second portion 32. The first portion of the door is the same as the first portion 21 of the biliary liquid crystal structure 2, and is composed of a plurality of 筮^^ 2121 phases and has a -th=not shown, each first Layer 8 has a first guide axis, and the first guide shaft is turned around, and the adjacent axis is called the first axis of the spiral axis 33. The direction of the glaze is different and is continuously changed - the distance between the two having the same first guide axis direction and the distance of the distance > 2 宕 宕 泛 哲 θ θ, which is the second pitch. This is a continuous change, and the pitch system is different and degrees. The first portion 31 is connected to the "one brother-one spiral ladder 1 to receive an incident light 34. The second portion 32 is composed of a plurality of second-second layers having a third (not shown) 'After each guide axis, the 笤笸-axis 35 rotates, the adjacent first--ankle axis is along the second transition between the second spiral state, and the two have the same second and different orientations. And being separated, defined by 2 times of the distance: the distance between the second layers in a * direction is different and is continuously changed, and the second - the second pitch systems are all rotated gradients. Preferably, 兮篦The change of a 'door' is a second snail 4 part of a 32-series 6 into 4 ^ system is the same as the first part of J05056.doc -J8-1289214 31, that is, the two materials are the same, and The first spiral gradient is equal to the second spiral gradient, and the second helical axis 35 is equal to the first helical axis 33. The thickness of the second portion 32 is the same as the thickness of the first portion 31, and is j.

&quot;Hai portion 31 and the second portion 32 form a defect plane 36. In this embodiment, the first portion 31 is connected to the defect plane and the first pitch is different from the second The portion U is connected to the second pitch on the defect plane %, and the pitch variation is discontinuous on the defect plane 36. That is, the first portion 31 and the second portion 32 have a pitch jump °, which is different from the first embodiment. In this embodiment, the pitch is added except for the pitch drop. a twist defect (or phse jump), that is, the direction of the first guide axis η of the first portion 31 on the defect plane % is different from the second portion of the a direction of the second guide axis η' on the defect plane %, and a phase difference (or a twist angle) is formed on the defect plane, which can be regarded as the first portion 31 and the second portion ^ Relative rotation of the misalignment angle α. Because of this, the spiral change and the pitch change immediately adjacent to the defect plane % are not continuous. Referring to Figure 10, the second twist angle of the cholesteric liquid crystal structure of the second embodiment is shown. The relationship between the wavelengths of the centers of the various defect modes, the total thickness s2 of the cholesteric liquid crystal structure 3 is "2 〇 Pmin. As can be seen from the figure, there is a linear relationship between the central wavelength position of the defect mode and the twist angle α. Referring to FIG. U, the second embodiment of the present invention shows the wearing of a cholesteric liquid crystal structure. Transmittance 4, where Μ = 2 咖 咖 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 12, showing the application of the present invention to an optical communication access network (Access Network) system. The optical communication access network system 4 is an important application in the optical fiber system to a fiber-to-the-home (Fiber-To-The-Home , FTTH), which is a value-added service that combines cable television (CATV) and high-speed network access. The optical communication access network system 4 includes an analog/digital TV broadcast transmitter (Analog/Digital TV Broadcast Transmitter) 4 1. An optical line terminal 42, an optical coupler 43, a single mode fiber 44, a filter 45, and a network terminal (〇 Ptical Netw〇rk Terminal 46, a cable TV (CATV) 47, a network unit (Optical Network Unit) 48, and a broadband network (ADSL/VDSL) 49. The analog/digital television transmitter 41, the optical path The terminal 42 and the optical coupler 43 are servo The network terminal 46, the cable TV 47, the network unit 48 and the broadband network 49 are clients. The first wavelength 4 transmitted by the analog/digital television transmitter 41 is 1555 nm, The second wavelength seven transmitted by the optical path terminal 42 is "% nm, and the first wavelength 4 and the second wavelength &amp; pass through the optical coupler" and then transmitted on the single mode fiber 44. The filter may be the cholesteric liquid crystal structure 2 of the first embodiment or the cholesteric liquid crystal structure 3 of the second embodiment. The filter characteristic of the filter 45 is circularly polarized, and in the case of a right-handed structure, the first wavelength 4 and the second wavelength V on the single-mode fiber 44 are to be divided. Select one of the four wavelengths as the defect mode. However, before the filter 45, the right circularly polarized light must be subjected to the photonic bandgap to generate chopping, so the light should be changed by a first phase delay of 105056.doc -20-1289214 (Phase Retarder) 50. The state of polarization. The separated first wavelength is passed to the cable 47 via the network terminal 46; the separated second wavelength is transmitted to the broadband network 49 via the network unit 48. The broadband network 49 returns to the path of the optical path terminal 42 with a wavelength of the second wavelength; 13 (13 3 0 nm), so no filtering is necessary. The polarization of the light should also be changed by a second phase retarder 5丨 after passing through the filter 45.

When the polarization is changed to the left circularly polarized light, it will not pass the photonic band gap and pass smoothly. Referring to Figure 13, there is shown a schematic diagram of a filter applied to a photo-plug multiplexer of the present invention. The optical plug multiplexer 6 includes a first spiral photonic crystal 7, a first spiral photonic crystal 8, and a half wavelength plate 9. In the present embodiment, the first spiral photonic crystal 7 is exemplified by a cholesteric liquid crystal structure which is the same as the cholesteric liquid crystal structure 2 of the first embodiment. The first spiral photonic crystal 7 includes a first portion 71 and a second portion 72. The first portion 71 of the first spiral photonic crystal 7 is identical to the first portion 21 of the cholesteric liquid crystal structure 2. The first portion 71 has a plurality of different first-pitches, and the first-pitch system is Continuous change. The second portion 72 is connected to the (four)-portion 71, and the first portion of the second portion 72 forms a --defect plane 73. The second portion 72 has a plurality of different portions. The second pitch 'the second pitch system is a continuous change, wherein the first pitch portion of the first portion 71 connected to the first defect plane is different from the second portion 72 connected to the first defect plane 73 The second pitch is formed, and the pitch variation is discontinuous on the first defect plane 73. In the present embodiment, the first spiral photonic crystal 8 is exemplified by a structure of cholesteric liquid crystal 105056.doc - 21. 1289214 which is the same as the cholesteric liquid crystal structure 2 of the first embodiment. The second spiral photonic crystal 8 package # a third portion 81 and a fourth portion 82 of the first thread photonic crystal 8 of the third portion 8 and the first portion of the cholesteric liquid crystal structure 2 the same. The third portion 81 has a plurality of different second snails 15' which are continuously varying. The fourth portion 82 is coupled to the third portion 81 and the third portion. A first defect plane 83 is formed with the fourth P-injury 82, the fourth portion having a plurality of different fourth pitches. The fourth pitch is a continuous change, wherein the first portion. The third pitch of the bruise 81 connected to the second defect plane 83 is different

The fourth pitch 82 of the province is connected to the fourth pitch on the second defect plane 83 to form a pitch variation discontinuity on the second defect plane 83. The one-half wavelength plate 9 is sandwiched between the first spiral photonic crystal 7 and the second spiral photonic crystal 8. The optical plug multiplexer 6 may not have circularly polarized light selectivity because the one-half wavelength slice 9 can exchange the polarization states of the right-handed light and the left-handed two orthogonal light regardless of the incident right. Both the optical rotation and the incident left-handed light must have a X-to-photon bandgap effect to produce a filtering effect, so that there is no circularly polarized light selectivity problem that can only produce half of the filtering effect. And to generate different wavelengths of filtering, only need to change the different twist angles "can be done, do not need to be like a conventional thin film filter must also be changed with different film thickness design. However, the above embodiments are only illustrative of the present invention The invention and its effects are not intended to limit the invention. Therefore, those skilled in the art can modify and change the above-described embodiments without departing from the spirit of the invention. The scope of the invention is 105056.doc 1289214 * #围应为为专利范围范围范围。 [Simple diagram of the diagram] Figure 1 a shows a spiral crystal structure of a climatic liquid crystal structure with a pitch gradient; Figure lb shows a liquid crystal with a pitch gradient of cholesteric liquid crystal structure Schematic diagram of the arrangement of molecular guide axes;

2 shows a transmission spectrum of a cholesteric liquid crystal structure having a pitch gradient; N | FIG. 3a is a schematic view showing the spiral structure of the spiral photonic crystal of the first embodiment of the present invention; and FIG. 3b is a view showing a liquid crystal molecule of the spiral photonic crystal of the first embodiment of the present invention. FIG. 4 shows a transmission spectrum of a helical photonic crystal according to a first embodiment of the present invention, wherein 2"20Pmin; FIG. 5 shows a transmission spectrum of a spiral photonic crystal of the first embodiment of the present invention, &gt; 2" Figure 6 shows the relationship between the cholesteric liquid crystal structure of different total thicknesses and the center wavelength of each defect mode in the same; Figure 7a shows the penetration spectrum of the cholesteric liquid crystal structure of the first embodiment of the present invention, wherein 2rf = l5Pmin; Figure 7b shows the present invention The penetration spectrum of the cholesteric liquid crystal structure of the first embodiment, wherein 2d = 45Pmin; Fig. 8 shows the breakthrough spectrum in the case of different incident angles of incident light in the cholesteric liquid crystal structure of the first embodiment of the present invention, wherein π = ; 105056. Doc -23- 1289214 Figure 9a is a perspective view showing a spiral photonic crystal of a second embodiment of the present invention; 2 is a schematic view showing a spiral structure of a spiral photonic crystal; FIG. 11 is a view showing a relationship between different twist angles and wavelengths of respective defect modes in the cholesteric liquid crystal structure of the second embodiment; FIG. 11 shows a cholesteric liquid crystal structure according to a second embodiment of the present invention. The penetration spectrum 'where 2i/ = 20Pmin; FIG. 12 shows a schematic diagram of the present invention applied to an optical communication access network system; and FIG. 13 shows the sound diagram of the filter applied to the optical plug-in multiplexer of the present invention. DESCRIPTION OF SYMBOLS] Λ First wavelength Λ Second wavelength Third wavelength 1 Cholesterol liquid crystal structure 2 The cholesteric liquid crystal structure of the first embodiment of the present invention The cholesteric liquid crystal structure of the second embodiment of the present invention 4 Optical communication access network system 6 Optical plug multiplexer 7 First spiral photonic crystal 8 Brother-helical photonic crystal 9 Half-wavelength plate 11 Spiral axis 105056.doc -24· 1289214 21 First part 22 Second part 23 First spiral axis 24 incident light 25 second helical axis 26 defect plane 31 first portion 32 second portion 33 first helical axis 34 incident light 35 second helical axis 36 Trap plane 41 analog/digital television transmitter 42 optical path terminal 43 optical coupler 44 single mode fiber 45 filter, wave 46 network terminal 47 cable TV 48 network unit 49 broadband network 50 first phase retarder 51 Second phase retarder 71 first part 105056.doc -25 - 1289214 72 73 81 82 83 211 212 221

I 222 Part 2 First defect plane Third part Fourth part Second defect plane First end face Second end face Third end face Fourth end face

105056.doc -26-

Claims (1)

1289214 X. Patent application scope: 1. A spiral photonic crystal comprising: a first portion having a plurality of non-pitch systems continuously varying; and a pitch, the first-second portion, and the first a portion of the phase &amp; 〃 forms a defect plane _ and a second pitch different from the first portion of the δH, the second pitch portion having a plurality of the first portion connected thereto The first variation of the defect is different from the first pitch of the first component connected to the defect plane, and the pitch variation is discontinuous on the defect plane. 2) For example, the spiral photonic crystal of item 1 is composed of 1 structure. , is a cholesterol liquid crystal junction 3. As in the spiral photonic crystal of claim 1, the sleeve @ a ^ T - Hai first part has a plurality of brothers one layer, the mother one first layer has a wall, # Α spear seed The direction of the axis between adjacent first layers is different and continuously changing. The second part has a plurality of second layers. Each second layer has a second guiding axis, and the adjacent first layer The direction of the two guiding axes is different and continuously changing, wherein the direction of the first guiding portion on the defect plane is different from the first portion, and the direction of the second guiding axis on the defect plane And a phase difference is formed on the defect plane. 4. The spiral photonic crystal of claim 1 wherein the first portion has a plurality of first layers 'each of the first layers has a first guide axis, and a direction of the first guide axis between adjacent first layers Different and continuously changing, the second part has a plurality of second layers, each of the first-eighth first layers has a dipole and a guide axis, adjacent to 105056.doc 1289214: the second guide axis between the layers The direction is different and varies continuously, wherein the direction of the first guide axis on the defect plane is the same as the direction of the second guide axis of the second portion on the defect plane. Such as the spiral photonic crystal of the requester, wherein the change between the first and the pitch of the first portion is a first spiral gradient, and the change between the second pitches of the second portion is a second a spiral gradient, the first spiral filter comprising a spiral photonic crystal, the spiral photonic crystal comprising: a first spiral axis, a first end surface and a second end surface, the first The end face is perpendicular to the first helical axis and receives an incident light. The first portion has a plurality of different first pitches, and the first pitches are continuously changed; The gradient is the same as the second spiral gradient? The two portions have a second helical axis, a third end surface and a fourth end surface, and the third end surface is connected to the second end surface of the first portion. The first flaw forms a defect plane between the second portion and the second portion, the second portion has a plurality of different second pitch gradients, and the second pitch is a continuous change, wherein the first portion is connected to the In the defect plane, the pitch-pitch is different from the second pitch of the second portion connected to the defect plane, and the pitch variation is discontinuous on the defect plane, and a portion of the incident light is from the fourth end face. The penetration is emitted, and another portion of the incident light is reflected by the first end surface. 7. The wave device of claim 6, wherein the spiral photonic crystal system is a cholesteric liquid crystal structure. 105056.doc 1289214 The filter of claim 6, wherein the angle between the incident light and the first helical axis of the first portion is 〇 to 2 degrees. The filter of claim 6, wherein the first portion has a plurality of first layers, each first layer has a first guiding axis, and the first direction between adjacent first layers is different and continuous Variation, the second portion has a plurality of layers, each second layer has a second guiding axis, and the direction of the adjacent second layer=the second guiding axis is different and continuously changes, wherein the first portion is connected The direction of the first guide axis on the defect plane is different from the direction of the first guide axis connected to the defect plane, and a phase difference is formed on the defect plane. 1 〇. As claimed in claim 6, the oil is crying, ^, and the wave state, wherein the first portion has a plurality of first ones: the first layer of the mother has a -th guide axis, and the adjacent first layer The first one: the system is different and continuously changes, the second part has a complex number two 'each second layer has a second guide axis, and the adjacent second layer 柃, * "the direction of the guide axis is different And in a continuous change 'where the first-part-neighbor = the direction of the first guide axis on the plane of the defect plane is the same as the direction of the second guide axis connected to the defect plane. For example, the filter of the sixth item, the change in the middle of the basin, the m visit (four) the first pitch of the pitch gate, the spiral gradient, the second part of the second code distance, the change of the grandmother _ one is the same as the 'flute' a spin gradient 'the first spiral gradient phase is opposite to the second spiral gradient. 12, the ferrite, comprising: a first spiral photonic crystal, comprising: the negative first P shares, having a plurality of different a pitch 105056.doc 1289214 - the second part is connected to the first part, and the first part is Forming a _th defect plane between the two parts, and (4) two parts having a plurality of different second pitches, wherein the second pitch is a continuous change 'where the first part is connected to the first defect plane The distance system is different from the second portion connected to the first defect plane a first distance, and a pitch continuous on the first defect plane; + a second spiral photonic crystal, comprising: a - third portion having a plurality of different third pitches, the second pitch systems being continuous Change; and a fourth part connected to the third part, and a third defect plane formed between the third part and the fourth part, and (four) four materials having a plurality of different fourth pitches, The fourth pitch is a continuous change, wherein the third pitch of the third portion connected to the second defect plane is different from the fourth pitch of the fourth portion connected to the second defect plane, and A pitch variation discontinuity is formed on the second defect plane; and a half-wavelength plate is sandwiched between the first spiral photonic crystal and the second spiral photonic crystal. 13. The filter of claim 12, wherein the first spiral photonic crystal and the first erbium photonic crystal system are cholesteric liquid crystal structures. 14. The filter of claim 12, wherein the first portion has a plurality of first layers, each first layer having a first lead axis, and a first 105056.doc -4- between adjacent first layers 1289214 v glaze direction is different and is the second layer, each second sound: = 'the second part has a plurality of second guide axis direction B - the second guide axis, adjacent ^ ^ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , A phase difference is formed on the plane of the first defect. σ is in the device of the requester 2, wherein the first spiral is in the second spiral photonic crystal. The same day-day optical communication network The system includes: · a servo end transmitting two or more wavelengths; - a client connected to the servo end by using an optical fiber; and a chopper located on the optical fiber at the servo end and the The H-skin between the clients has a spiral photonic crystal as claimed in item i to distinguish the ones from the servo end The wavelength is sent to the client. 17. The optical communication system of claim 16, wherein the (5) server comprises a analog/digital television transmitter, an optical path terminal, and an optical coupler. 18. The optical communication access system of claim 16, wherein the client comprises a network terminal, a cable television, a network unit, and a broadband network. The network system further includes a first phase retarder 'between the buffer end and the ferrite to change the polarization state of the light. 2 0 · The optical communication system of claim 16 is connected to the network system, There is further included a second phase 105056.doc 1289214 to change the retarder of the light between the client and the filter, the polarization state. 105056.doc