201011358 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種光纖，特別是關於一種光子晶體光 纖（photonic crystal fiber)。 【先前技術】 目前，由於光纖具有製作成本低廉、可同時傳輸多個 訊號而各訊號不會彼此干擾，以及不易受到外來訊號干擾 0 等優點，因此已廣泛應用於資訊傳輸方面。 然而’光線在光纖中進行傳輸，該光線將產生色散， 且色散值係為正值，使該光線之波形產生變化，且該變化 係與傳輸距離成正比；而一般習用光子晶體光纖之色散值 係為負的數百ps/nm-km左右，因此，可進一步應用於色散 補償，以補償該光纖於傳輸過程中所產生之正的色散值。 請參照第1圖所示，一般習用光子晶體光纖9之橫截 面係為圓形，其係包含一芯部91及數個中空管部92，該 〇 芯部91係位於該光子晶體光纖9之中央；該數個中空管部 92係平行該芯部91延伸，並在徑向上圍繞於該芯部91之 外圍’且該數個管部92係在徑向剖面上以該芯部91為中 •“排列形成數圈正六邊形，該中空管部92内係充填空氣， 該光子晶體光纖9係以折射率大於i之材質製成，如此， 由該光子晶體光纖9之芯部91的一端入射一光線，則 ㈣芯部91及該中空管部92之折射率差異而於該芯部％ 管部92產生全反射，使該规可_於該怒部 201011358 另一習用光子晶體光纖，係於該芯部91中摻雜其他 材質，以提升該芯部91與該中空管部92之折射率差異， 進而達到負的色散值。 上述習用光子晶體光纖具有下列缺點，例如：由於該 習用光子晶體光纖之色散值僅達負的數百ps/nm-km左右 ，其負值相對不足，因此需要較長之光子晶鱧光纖，方可 補償該光線因傳輸所產生之正的色散值；再者，該光子晶 ❹ 體光纖一旦製作完成後，其色散特性便固定而無法改變， 因此無法針對不同之應用狀態下改變特性，造成其具有應 用範圍狹窄之缺點。基於上述原因，其確實有必要進一步 改良上述光子晶體光纖。 【發明内容】 本發明之主要目的係提供一種光子晶體光纖，以提升 色散補償效果及提升應用範圍。 為了達到上述之發明目的，本發明的技術手段係於該 〇 光子晶體光纖中的數圈管部之其中一圈的管部内填充入一 液體，使該光子晶體光纖形成雙纖心結構，進而使該光子 晶體光纖可具有絕對值相當大之負色散值，以提升色散補 償效果，同時亦可利用調整溫度改變該液體特性而控制該 光子晶體光纖之最大色散補償波長及色散值大小。 根據本發明之光子晶體光織，係包含：一芯部及數個 管部，該芯部係設置於該光子晶體光纖之中央；該數個管 部轴向延伸於該光子晶體光纖中，且平行該芯部該數個 管部在徑向剖面上以該芯部為中心排列形成數圈正六邊形 201011358 層疊圍繞該芯部；其中，任二相鄰之管部之間的距離係為 相同，且形成其中一圈正六邊形之數個管部内係填充有一 液體，而該液體之折射率係小於該芯部之折射率，並大於 空氣之折射率。藉此，可大幅提升色散補償效果及提升應 用範圍。 【實施方式】 為讓本發明之上述及其他目的、特徵及優點能更明顯 易懂，下文特舉本發明之較佳實施例，並配合所附圖式， 作詳細說明如下：請參照第2及3圖所示，本發明較佳實 施例之光子晶體光纖1係包含一芯部n及數個管部12， 該芯部11係可選擇以玻璃製成，如第3圖所示，其係為本 發明之光子晶體光纖1之橫截面，該芯部n係位於該光子 晶體光纖1之軸心位置，以作為該光子晶體光纖j之纖心 、，該數個管部12為中空管部，其係平行該芯部n延伸， 並在徑向剖面上圍繞於該芯部u之外圍，且該數個管部 Q 12係排列形成週期性結構。於本實施例中，該數個管部12 係在徑向上以該芯部11為中心排列形成數圈正六邊形，且 任二相鄰之管部12之間之距離皆為間距d。此外，形成其 中一圈正六邊形之數個管部12中係填充有一液體13，該 液體13較佳係選擇為一折射液，例如本實施例之液體係選201011358 IX. Description of the Invention: [Technical Field] The present invention relates to an optical fiber, and more particularly to a photonic crystal fiber. [Prior Art] At present, optical fibers have been widely used in information transmission because of their low production cost, simultaneous transmission of multiple signals, interference of signals, and difficulty in interference from external signals. However, 'light is transmitted in the fiber, the light will produce dispersion, and the dispersion value is positive, causing the waveform of the light to change, and the variation is proportional to the transmission distance; and the dispersion value of the conventional photonic crystal fiber is generally used. It is about hundreds of ps/nm-km, so it can be further applied to dispersion compensation to compensate for the positive dispersion value produced by the fiber during transmission. Referring to FIG. 1, a conventional photonic crystal fiber 9 has a circular cross section, and includes a core portion 91 and a plurality of hollow tube portions 92, and the core portion 91 is located on the photonic crystal fiber 9. The plurality of hollow tube portions 92 extend parallel to the core portion 91 and radially surround the periphery of the core portion 91 and the plurality of tube portions 92 are in a radial cross section with the core portion 91 The middle portion of the hollow tube portion 92 is filled with air. The photonic crystal fiber 9 is made of a material having a refractive index greater than i. Thus, the core of the photonic crystal fiber 9 is formed. When one end of 91 is incident on a light, (4) the refractive index difference between the core portion 91 and the hollow tube portion 92 is totally reflected at the core portion of the core portion 92, so that the rule can be used for another conventional photon of the anger portion 201011358 The crystal fiber is doped with other materials in the core portion 91 to increase the refractive index difference between the core portion 91 and the hollow tube portion 92, thereby achieving a negative dispersion value. The conventional photonic crystal fiber has the following disadvantages, for example, : Since the dispersion value of the conventional photonic crystal fiber is only a few hundred ps/nm - About km, the negative value is relatively insufficient, so a longer photonic crystal fiber is needed to compensate for the positive dispersion value of the light due to transmission; further, once the photonic crystal fiber is fabricated, its dispersion The characteristics are fixed and cannot be changed, so the characteristics cannot be changed for different application states, which has the disadvantage of narrow application range. For the above reasons, it is indeed necessary to further improve the above photonic crystal fiber. [Summary of the Invention] The object of the invention is to provide a photonic crystal fiber for improving the dispersion compensation effect and improving the application range. In order to achieve the above object, the technical means of the invention is in the tube portion of one of the loop portions of the 〇 photonic crystal fiber. The liquid crystal fiber is filled into a double core structure, so that the photonic crystal fiber can have a negative value of a large absolute value to enhance the dispersion compensation effect, and the liquid temperature can be changed by adjusting the temperature. Controlling the maximum dispersion compensation wavelength and dispersion value of the photonic crystal fiber The photonic crystal optical woven fabric according to the present invention comprises: a core portion and a plurality of tube portions disposed at a center of the photonic crystal fiber; the plurality of tube portions extending axially in the photonic crystal fiber, Parallel to the core, the plurality of tube portions are arranged on the radial cross section with the core portion as a center to form a plurality of regular hexagons 201011358 laminated around the core portion; wherein the distance between any two adjacent tube portions is The same is formed, and a plurality of tubes forming one of the regular hexagons are filled with a liquid, and the refractive index of the liquid is smaller than the refractive index of the core and larger than the refractive index of the air. Thereby, the dispersion compensation can be greatly improved. The above and other objects, features, and advantages of the present invention will become more apparent from the embodiments of the invention. As shown in FIGS. 2 and 3, the photonic crystal fiber 1 of the preferred embodiment of the present invention comprises a core portion n and a plurality of tube portions 12, and the core portion 11 is optionally made of glass, such as In the figure 3, it is In the cross section of the photonic crystal fiber 1 of the present invention, the core portion n is located at the axial center of the photonic crystal fiber 1 as the core of the photonic crystal fiber j, and the plurality of tube portions 12 are hollow tubes. It extends parallel to the core n and surrounds the periphery of the core u in a radial cross section, and the plurality of tube portions Q 12 are arranged to form a periodic structure. In the present embodiment, the plurality of tube portions 12 are arranged in the radial direction with the core portion 11 as a center to form a plurality of regular hexagons, and the distance between any two adjacent tube portions 12 is the distance d. Further, a plurality of tube portions 12 forming a regular hexagon in the circle are filled with a liquid 13, and the liquid 13 is preferably selected as a refractive liquid, for example, the liquid system of the present embodiment is selected.
擇為Casgille Labs所生產之型號為a、AA、AAA、B、E 、Η、EH、FG、GH或Μ系列之折射液，該液體13之折 射率係小於該芯部11之折射率，且大於空氣之折射率其 他圈之數個管部12内係存有空氣。 、 201011358 如此，該填充有液體13之管部12便可形成一第二織 心，使本發明之光子晶體光纖1為雙纖心結構，利用該雙 纖心結構具有兩個模態之特性’當該二模態在相位上互相 匹配時，亦即該心》卩11之光線能量開始輕合（e〇Upling) 至該填充有液體13之管部12時，便可產生絕對值相當大 的負色散值’以供應用於色散補償上。再且，由於調整溫 度將可改變該液體之特性，進而調整最大色散補償波長及 ❹ 色散值之大小，因此可增進應用範圍。 本發明另進行下述分析，以驗證本發明之光子晶體光 纖1可產生絕對值相當大的負色散值，且可利用溫度變化 而調整最大色散補償波長及色散值之大小。其中，進行下 述分析之光子晶體光纖1之芯部n外圍係設置有7圈正六 邊形之管部12 ,本實施例將於第4圈之管部12内填充有 液體13 ’該管部12之直徑係為i 2腿，且該間距d係為 2.3mm，其中，所謂第4圈之管部12係指由該芯部Π向 ® *卜數第4圈正六邊形之管部12，其他以此類推，不再贅述 〇 請參照第4圖所示，其係為本發明之光子晶體光纖1 之波長（ym)相對色散值之變化圖其中 ，M三組填充有不同折射率之液體的光子晶體光纖1進行 ^較’分別為第a、b及c組，第3組所填充之液體13的 射率係為1.测；第b組所填充之液體13的折射率係為 笛3875 ;第C組所填充之液體13的折射率係為1.3866。由 圖、，果可得知，第a、b及c組之色散值皆達-17500 201011358 ps/nm-km。相較於習知光子晶體光纖之色散值僅能達到約 負的數百ps/nm-km，本發明之色散值明顯為習知光子晶體 光纖之色散值的數百倍，若將本發明之光子晶體光纖1應 用於色散補償應用上，可有效減短色散補償元件之長度並 減少損耗。 請參照第5圖所示，其係為本發明之光子晶體光纖i 於不同液體13之折射率下，波長或色散值之變化圖。由第 5圖之實線可得知，且當該液體13之折射率越高，具有最 大色散補償之光的波長越小；由第5圖之虛線可得知，當 該液體13之折射率越高，最大色散補償之負的色散值越佳 ,亦即該負的色散值的絕對值越大。亦可驗證本發明之光 子晶體光纖1具有極佳的色散補償能力。 請參照第6圖所示，其係為本發明之光子晶體光纖1 之波長（以m)相對色散值（ps/nm_km)之變化圖，於本 分析中，該光子晶體光纖1所填充之液體13的折射率均為 1.3875 ’以該光子晶體光纖1於三種不同溫度下進行比較 ’分別為第e、f及g組，第e組係於17.5。(：之環境下進行 分析；第f組係於25Ϊ之環境下進行分析；第g組係於32.5 C之環境下進行分析。由結果可得知，第e、f及g組三者 之折射率最佳皆低於-15〇〇〇ps/nm-km，亦可驗證本發明之 光子晶體光纖1具有極佳的色散補償能力。 請參照第7圖所示，其係為本發明之光子晶體光纖1 之溫度（。〇相對波長（//m)之變化圖。由結果可得知 ’且當該環境溫度越高，具有最大色散補償之光波長值就 201011358 越大。藉此，可驗證本發明之光子晶體光纖丨確實可於不 同之環境溫度下表現出不同之特性，使用者可依照輸入光 的不同波長值透過控制溫度來調整該光子晶體光纖丨之最 大色散補償之光波長範圍與該輸入光的波長值相符，以提 升其色散補償能力》 請參照第8圖所示，其係為本發明之光子晶體光纖i 之波長相對色散值的變化圖，其中，於本分析中，該光子 ❹ 晶體光纖1係分別於第3、4及5圈之管部12内填充折射 率係為1.3875之液體13，分別為第h、i及j組，第h組 係於第3圈之管部12内填充液體13;第丨組係於第4圈之 管部12内填充液體13 ;第j組係於第5圈之管部12内填 充液體13。由結果可得知，填充有液體13之圈數越大， 該光子晶體光纖1之色散值亦向負值逐漸增加，例如，第 j組之色散值可達_275〇〇 pS/nm-km，但其最大色散補償之 光波長範圍也越窄；反之，第i組之色散值雖僅達_185〇〇 〇 ps/nm-km，但其最大色散補償之光波長範圍相較大於第』 組之最大色散補償之光波長範圍。因此，其驗證本發明之 光子晶體光纖1除了具有極佳的色散補償能力之外，使用 者亦可經由調整該第二纖心與該芯部u之間的距離，以取 得最適當的最大色散補償之光波長範圍及最佳色散值。 此外’本發明之光子晶體光纖1之芯部11當然亦可摻 雜其他折射率折射率高於該光子晶體光織之折射率的材質 ，以提升該芯部11與其他部位之折射率差異，進而提升該 光子晶體光纖1之色散補償能力。 201011358 如上所述’本發明之光子晶體光織1利用於該數圈之 數個管部12中’將其中一圈之管部12中填充入液體13， 使該填充有液體13之管部π形成一第二纖心，如此，當 該芯部11及該另一纖心形成相位匹配時，該光子晶體光織 1可具有絕對值相當大之負的色散值，可提升色散補償之 效率；再者’該液體13將隨環境溫度之改變而產生特性上 的變化，因此’可透過調整溫度而改變該光子晶體光纖i 之特性’進而有效提升該光子晶體光纖i之應用範圍。 雖然本發明已利用上述^^佳實施例揭示，然其並非用 以限定本發明，任何熟習此技藝者在不脫離本發明之精神 和範圍之内’相對上述實施例進行各種更動與修改仍屬本 發明所保護之技術範疇，因此本發明之保護範圍當視後附 之申請專利範圍所界定者為準。 201011358 【圖式簡單說明】 第1圖：習用光子晶體光纖之立體剖面圖。 第2圖：本發明較佳實施例之光子晶體光纖之立體剖面 圖。 第3圖：本發明較佳實施例之光子晶體光纖之剖面圖。 第4圖.本發明較佳實施例之光子晶體光纖之波長（私 m)相對色散值（pS/nm_km)之變化圖。The refractive index of the model a, AA, AAA, B, E, Η, EH, FG, GH or Μ series produced by Cagille Labs, the refractive index of the liquid 13 is smaller than the refractive index of the core 11, and Air is stored in a plurality of tube portions 12 that are larger than the refractive index of air. Thus, 201011358, the tube portion 12 filled with the liquid 13 can form a second weave, so that the photonic crystal fiber 1 of the present invention has a double core structure, and the double core structure has two modal characteristics. When the two modes match each other in phase, that is, the light energy of the heart 卩11 starts to lighten (e〇Upling) to the tube portion 12 filled with the liquid 13, the absolute value is relatively large. The negative dispersion value 'is supplied for dispersion compensation. Moreover, since the adjustment of the temperature can change the characteristics of the liquid, and thereby adjust the maximum dispersion compensation wavelength and the ❹ dispersion value, the application range can be improved. The present invention further performs the following analysis to verify that the photonic crystal fiber 1 of the present invention can produce a negative value having a relatively large absolute value, and the maximum dispersion compensation wavelength and the dispersion value can be adjusted by the temperature change. Here, the core portion n of the photonic crystal fiber 1 subjected to the following analysis is provided with a 7-turn hexagonal tube portion 12, and in this embodiment, the tube portion 12 of the fourth ring is filled with a liquid 13'. The diameter of 12 is i 2 legs, and the pitch d is 2.3 mm. The tube portion 12 of the fourth ring refers to the tube portion 12 which is bent by the core to the fourth circle of the regular hexagon. The other three are filled with different refractive indices. The liquid photonic crystal fiber 1 is made to be a group a, b, and c, respectively, and the liquid rate of the liquid 13 filled in the third group is 1. The refractive index of the liquid 13 filled in the b group is Flute 3875; Group C filled liquid 13 has a refractive index of 1.3866. As can be seen from the figure, the dispersion values of groups a, b and c are all -17500 201011358 ps/nm-km. Compared with the conventional photonic crystal fiber, the dispersion value can only reach about a few hundred ps/nm-km, and the dispersion value of the present invention is obviously hundreds of times the dispersion value of the conventional photonic crystal fiber. Photonic crystal fiber 1 is applied to dispersion compensation applications, which can effectively shorten the length of dispersion compensation components and reduce losses. Please refer to FIG. 5, which is a graph showing changes in wavelength or dispersion value of the photonic crystal fiber i of the present invention at a refractive index of different liquids 13. As can be seen from the solid line in Fig. 5, and the higher the refractive index of the liquid 13, the smaller the wavelength of the light having the maximum dispersion compensation; the dotted line of Fig. 5 shows the refractive index of the liquid 13 The higher the dispersion value of the negative dispersion compensation, the greater the absolute value of the negative dispersion value. It was also confirmed that the photonic crystal fiber 1 of the present invention has excellent dispersion compensation ability. Please refer to FIG. 6 , which is a graph showing the change of the wavelength (in m) relative dispersion value (ps/nm_km) of the photonic crystal fiber 1 of the present invention. In the present analysis, the liquid filled by the photonic crystal fiber 1 is The refractive index of 13 is 1.3875 ', and the photonic crystal fiber 1 is compared at three different temperatures', respectively, in groups e, f, and g, and group e is at 17.5. (The analysis was carried out in the environment; the f group was analyzed in an environment of 25 ;; the g group was analyzed in the environment of 32.5 C. From the results, the refraction of the three groups e, f and g The best rate is lower than -15 〇〇〇 ps/nm-km, and it can also be verified that the photonic crystal fiber 1 of the present invention has excellent dispersion compensation capability. Referring to Fig. 7, it is a photon of the present invention. The temperature of the crystal fiber 1 (. 〇 relative wavelength (//m) change graph. It can be known from the results' and the higher the ambient temperature, the larger the wavelength value of the light with the maximum dispersion compensation is 201011358. It is verified that the photonic crystal fiber 本 of the present invention can exhibit different characteristics at different ambient temperatures, and the user can adjust the wavelength range of the maximum dispersion compensation of the photonic crystal fiber by controlling the temperature according to different wavelength values of the input light. Corresponding to the wavelength value of the input light to improve the dispersion compensation capability. Please refer to FIG. 8 , which is a variation diagram of the wavelength relative dispersion value of the photonic crystal fiber i of the present invention, wherein, in this analysis, The photon twin The bulk fiber 1 is filled with the liquid 13 having a refractive index of 1.3875 in the tube portions 12 of the third, fourth and fifth turns, respectively, in groups h, i and j, and the h group is in the tube portion 12 of the third ring. The inner filling liquid 13; the second group is filled with the liquid 13 in the tube portion 12 of the fourth ring; the j group is filled with the liquid 13 in the tube portion 12 of the fifth ring. As a result, it can be known that the liquid 13 is filled. The larger the number of turns, the dispersion value of the photonic crystal fiber 1 is also gradually increased to a negative value. For example, the dispersion value of the jth group can reach _275〇〇pS/nm-km, but the wavelength range of the maximum dispersion compensation light is also The narrower; conversely, the dispersion value of the i-th group is only _185 〇〇〇ps/nm-km, but the wavelength range of the maximum dispersion compensation is larger than the wavelength range of the maximum dispersion compensation of the 』 group. In addition to the excellent dispersion compensation capability of the photonic crystal fiber 1 of the present invention, the user can also adjust the distance between the second core and the core u to obtain the most appropriate maximum dispersion compensation. The wavelength range of the light and the optimum dispersion value. Further, the core portion 11 of the photonic crystal fiber 1 of the present invention may of course be doped. A material having a refractive index higher than a refractive index of the photonic crystal to increase the refractive index difference between the core 11 and other portions, thereby improving the dispersion compensation capability of the photonic crystal fiber 1. 201011358 The photonic crystal woven fabric 1 is used in the plurality of tube portions 12 of the plurality of turns to 'fill one of the tube portions 12 into the liquid 13 so that the tube portion π filled with the liquid 13 forms a second core. Thus, when the core 11 and the other core form a phase matching, the photonic crystal optical woven 1 can have a negative value of a relatively large absolute value, which can improve the efficiency of dispersion compensation; The change in characteristics occurs as the ambient temperature changes, so that the 'characteristic of the photonic crystal fiber i can be changed by adjusting the temperature', thereby effectively increasing the application range of the photonic crystal fiber i. Although the present invention has been disclosed in the above-described embodiments, it is not intended to limit the invention, and various modifications and changes may be made to the above-described embodiments without departing from the spirit and scope of the invention. The technical scope of the present invention is therefore intended to be defined by the scope of the appended claims. 201011358 [Simple description of the diagram] Figure 1: A three-dimensional cross-sectional view of a conventional photonic crystal fiber. Figure 2 is a perspective cross-sectional view of a photonic crystal fiber in accordance with a preferred embodiment of the present invention. Figure 3 is a cross-sectional view of a photonic crystal fiber in accordance with a preferred embodiment of the present invention. Fig. 4 is a graph showing changes in wavelength (private m) relative dispersion value (pS/nm_km) of a photonic crystal fiber according to a preferred embodiment of the present invention.
❹ 第5圖·本發雜佳實施例之光子晶體光麟不同液體 之折射率下，波長或色散值之變化圖。 第6圖··本個較佳實施例之光子晶體光纖之波長（私 m)相對色散值（ps/nm-km)之變化圖。 第7圖·本發明較佳實施例之光子晶體光纖之溫度⑺ )相對波長（#m)之變化圖。 第8圖·本發赚佳實施例之光子晶體光纖之波長（私 m)相對色散值（ps/nm-km)的變化圖。 【主要元件符號說明】 11芯部 13液體 91芯部 d 間距 1 光子晶體光纖 12管部 9 光子晶體光纖 92中空管部 —12 —❹ Fig. 5 is a graph showing the change in wavelength or dispersion value at the refractive index of different liquids of photonic crystals of the present invention. Fig. 6 is a graph showing changes in the relative dispersion value (ps/nm-km) of the wavelength (private m) of the photonic crystal fiber of the preferred embodiment. Fig. 7 is a graph showing changes in temperature (7) versus wavelength (#m) of a photonic crystal fiber according to a preferred embodiment of the present invention. Fig. 8 is a graph showing changes in the relative dispersion value (ps/nm-km) of the wavelength (private m) of the photonic crystal fiber of the present embodiment. [Main component symbol description] 11 core 13 liquid 91 core d Spacing 1 Photonic crystal fiber 12 tube 9 Photonic crystal fiber 92 hollow tube —12 —