201003113 . 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種膜堆結構，尤指一種應用於分光棱鏡 上之膜堆結構。 【先前技術】 目前’光學鍍膜已經被廣泛地運用於投影機、傳統相 機、數碼相機、手機、天文望遠鏡所用之鏡頭組、濾光片 等’用來使得這些光學元件能夠實現不同之光學功能，例 如：吸收紫外線、減反射、彩色濾光、紅外光截止等。 如圖1所示，本發明涉及一種應用於分光棱鏡1中之 膜堆結構2。該分光棱鏡χ用於各種光學儀器之顏色分離系 統。外界光線進入分光棱鏡i後以45度角入射到鍍有膜堆 結構2之表面3上，在透射波長範圍内之光線透過該膜堆 結構2由分光棱鏡i之上表面4射出，在反射波長範圍内 之光線被該臈堆結構2反射由分光棱鏡丄之侧面5射出從 而達到分光濾波之效果。 π現有之膜堆結構2通常使用高、低折射率材料交互層 丘之週期!·生結構。該膜堆結構2可表示為(瓜)”，其中，Η 代表高折射率膜層，L代表低折射率膜層。l前面之 係數之比表示各自折射率膜層之光學厚度比，該光學厚声 :物理意義為膜層物理厚度與膜層折射率之乘積，光學P 度1等於參考波县夕·!u μ 九千& 嗲古折射率鉍Μ 。上裇11表示（瓜)”結構之週期數。 3率材料之折射率大於^而低折射率材料之折射 5 201003113 率低於1.5。 如圖2所示’其為參考波長為550nm，入射角為45度 時週期數為18之膜堆結構2(ffi)18之透射光譜圖。其中，實 線為自然光之透射光譜線，虛線為平行偏振光（p_p〇larized) 之透射光譜線，點劃線為垂直偏振光（s_Polarized)之透射 光譜線。該垂直偏振光為線偏振光，其偏振面垂直於由濾 光片表面法線和入射光線所決定之平面。該平行偏振光為 線偏振光，其偏振面平行於垂直偏振光之偏振面。自然光 可看成係振幅相同之平行偏振光（p_p〇larized )與垂直偏振 光（S-Polarized)之疊加。因為波長相同之垂直偏振光與平 行偏振光對於同一種材料所呈現之折射率不同，所以會導 致透過該膜堆結構2(m)18之平行偏振光譜特性與垂直偏振 光4特性產生偏移，即圖2中之虛曲線和點劃線在波長方 向上出現平移，該平行偏振光透射光譜線之半值波長（透 過率為50%時所對應之波長）與垂直偏振光透射光譜線之 半值波長相差70nm以上。此時，混合後自然光之透射光譜 線會在半值波長處出現非線性之不平滑部分影響了分光濾 波之效果。 因為光學系統中之光源所發出之平行光通常存在一定 之角度誤差，所以分光濾波膜堆之透射光譜特性隨入射光 線角度之變化情況也成為考察分光濾波膜堆品質好壞之標 準之一。 現以入射角分別為53度和37度為例，考察該膜堆結 構2(itt)18之透射光譜特性隨入射光線角度之變化情況。如 6 201003113 圖3、圖4所示，其中，實線為自然光之透射光譜線，虛線 為平行偏振光之透射光譜線，點劃線為垂直偏振光之透射 光譜線。從圖3中可知’當入射角度較大（入射角為53度） 時，該膜堆結構2(ffl)18之自然光透射光譜線之非線性不平 滑部分更為明顯，而且反射波長範圍之反射率也降低許 多。從圖3和圖4之對比中可發現，該膜堆結構2之透射 光譜特性隨角度變化明顯，若以透過率為3〇%時所對應之 波長做比較，入射角為53度時之自然光透射光譜線與入射 角為37度時之自然光透射光譜線相差8〇nm。 、綜上所述，現有之膜堆結構2(/江)18因高、低折射率材 料之折射率存在較大差異從而導致其出現分域波之效果 較差，透射光譜特性隨角度變化明顯以及在大角度入射時 反射波段之反射率下降等缺點。 【發明内容】 有鑒於此 堆結構。 有必要提供具有較理想分㈣波效果之膜 -種膜堆結構，該膜堆結構包括—個透明基底和疊於 :=週期性Μ堆。該週期性膜堆之週期性結 之折射率範圍為仫71至1·79或1.81至186。201003113. IX. Description of the Invention: [Technical Field] The present invention relates to a membrane stack structure, and more particularly to a membrane stack structure applied to a beam splitting prism. [Prior Art] At present, 'optical coating has been widely used in projectors, conventional cameras, digital cameras, mobile phones, lens sets used for astronomical telescopes, filters, etc.' to enable these optical components to achieve different optical functions, For example: absorption of ultraviolet light, anti-reflection, color filter, infrared light cut-off, etc. As shown in Fig. 1, the present invention relates to a film stack structure 2 applied to a beam splitting prism 1. The dichroic prism is used in color separation systems for various optical instruments. After the external light enters the beam splitting prism i, it is incident on the surface 3 coated with the film stack structure 2 at an angle of 45 degrees, and the light in the transmission wavelength range is transmitted through the film stack structure 2 from the upper surface 4 of the beam splitting prism i at the reflection wavelength. The light in the range is reflected by the stack structure 2 and is emitted from the side 5 of the beam splitting prism to achieve the effect of spectral filtering. π The existing membrane stack structure 2 usually uses high and low refractive index materials to alternate the cycle of the layers! The film stack structure 2 can be represented as (cucumber), wherein Η represents a high refractive index film layer, and L represents a low refractive index film layer. The ratio of the coefficients in front of the film represents the optical thickness ratio of the respective refractive index film layers, the optical Thick sound: The physical meaning is the product of the physical thickness of the film and the refractive index of the film. The optical P degree is equal to the reference wave county ‧·u μ nine thousand & the ancient refractive index 铋Μ. The upper 裇11 indicates (melon)” The number of cycles of the structure. The refractive index of the 3 rate material is greater than ^ and the refractive index of the low refractive index material 5 201003113 The rate is lower than 1.5. As shown in Fig. 2, it is a transmission spectrum diagram of a film stack structure 2 (ffi) 18 having a reference wavelength of 550 nm and a period of incidence of 45 degrees. The solid line is the transmission spectrum line of natural light, the broken line is the transmission spectrum line of parallel polarized light (p_p〇larized), and the dotted line is the transmission spectrum line of vertically polarized light (s_Polarized). The vertically polarized light is linearly polarized light having a plane of polarization perpendicular to a plane defined by the normal to the surface of the filter and the incident ray. The parallel polarized light is linearly polarized light whose plane of polarization is parallel to the plane of polarization of the vertically polarized light. Natural light can be seen as a superposition of parallel polarized light (p_p〇larized) and vertically polarized light (S-Polarized) with the same amplitude. Since the vertically polarized light of the same wavelength and the parallel polarized light exhibit different refractive indices for the same material, the parallel polarization spectral characteristics transmitted through the film stack structure 2(m) 18 are shifted from the characteristics of the vertically polarized light 4, That is, the dashed curve and the alternate long and short dash line in FIG. 2 have a translation in the wavelength direction, and the parallel polarized light transmits the half value wavelength of the spectral line (the wavelength corresponding to the transmittance of 50%) and the half of the vertical polarized light transmission spectral line. The value wavelengths differ by more than 70 nm. At this time, the non-smooth portion of the transmission spectrum of the natural light after mixing at a half-value wavelength affects the effect of the spectral filtering. Because the parallel light emitted by the light source in the optical system usually has a certain angular error, the variation of the transmission spectral characteristics of the spectral filter film stack with the incident light angle has become one of the criteria for examining the quality of the spectral filter film stack. Taking the incident angles of 53 degrees and 37 degrees as examples, the transmission spectral characteristics of the stack structure 2 (itt) 18 are observed as a function of incident light angle. As shown in Fig. 3 and Fig. 4, the solid line is the transmission spectrum line of natural light, the broken line is the transmission spectrum line of parallel polarized light, and the dotted line is the transmission spectrum line of vertically polarized light. It can be seen from Fig. 3 that when the incident angle is large (incident angle is 53 degrees), the nonlinear non-smooth portion of the natural light transmission spectral line of the film stack structure 2 (ffl) 18 is more obvious, and the reflection wavelength range is reflected. The rate is also much lower. It can be seen from the comparison between FIG. 3 and FIG. 4 that the transmission spectrum characteristic of the film stack structure 2 varies significantly with angle, and if the wavelength corresponding to the transmittance is 3〇%, the natural light at an incident angle of 53 degrees is compared. The transmission spectral line differs from the natural light transmission spectral line at an incident angle of 37 degrees by 8 〇 nm. In summary, the existing membrane stack structure 2 (/Jiang) 18 has a large difference in the refractive index of the high- and low-refractive-index materials, resulting in a poor effect of the occurrence of the delocalized wave, and the transmission spectral characteristics vary significantly with the angle and Disadvantages such as a decrease in the reflectance of the reflection band at a large angle of incidence. SUMMARY OF THE INVENTION This stack structure is contemplated. It is necessary to provide a membrane-membrane stack structure having a better sub-four wave effect, the stack structure comprising a transparent substrate and a stack of := periodic stacks. The periodic junction of the periodic film stack has a refractive index ranging from 仫71 to 1.79 or 1.81 to 186.
^較於先前之技術，該膜堆結構制了中 層代替現有之膜堆結構中之低折射率臈層，減=性 膜堆結構中兩種折射率膜層之間之折射率差值，齡H 201003113 . 射垂直偏振光譜和透射平行偏振光譜之差距，達到改善分 . 光濾波鏡之透射光譜特性之目之。 【實施方式】 請參閱圖5，其為本發明所提供之膜堆結構10示意 圖。該膜堆結構10包括透明基底102和疊於其上之週期性 膜堆104。該週期性膜堆104之週期性結構為交互層疊之高 折射率膜層106和中間折射率層108。該週期性膜堆104 之週期性結構可表示為（付M)%其中，Η代表一個高折射率膜 層106，Μ代表一個中間折射率膜層104，Η和Μ前面之係 數之比代表各折射率膜層之光學厚度比，上標η表示該週 期性結構之週期數。 該週期性膜堆104 (/^〇”之高折射率膜層106和中間折 射率膜層108之光學厚度相同。該週期性膜堆104(//Μ)"之 週期數根據需要透射和反射之波長範圍而設定。於本實施 例中，該週期性膜堆104(//Μ)"之週期數為18，其透射之波 長範圍為480nm至670nm，反射之波長範圍為400nm至 440nm ° 該透明基底102之材料可為透明玻璃或塑膠材質，如 無色高度透明之冕玻璃（B270)或者青板玻璃。高折射率 膜層106之折射率大於2.1，其材料可為二氧化鈦、五氧化 二钽和五氧化二鈮中之一種。中間折射率膜層108之折射 率範圍為1.71至1.79或1.81至1.86，其材料可為德國默 克公司生產之中間折射率材料M2或M3。除了本實施方式 201003113 *所提到之材料外，其他能滿足各膜層折射率要求之材料也 ，可採用，各膜層通過物理氣相沉積之方法制得。 請參閱圖6,其為週期性膜堆1〇4(胃)18在參考波長為 475nm，入射角為45度條件下之透射光譜圖。其中，實線 為自然光之透射光譜線，虛線為平行偏振光之透射光譜 線，點劃線為垂直偏振光之透射光譜線。對比圖6與圖2 可知，該週期性膜堆104(/ο/Γ透射之平行偏正光譜線與垂 直偏振光谱線之半值波長差值僅為4〇nm。相較於有 結構，本發明提供之週期性膜堆1〇4(_广大大地減 少了平行偏振光譜線和垂直偏振光譜線之偏移效應，使得 透過該週期性膜堆104(//M)18之自然光之光譜特性在半值波 長處之非線性不平滑部分得到較大之改善，提高了該週期 性膜堆1〇4(胃广之分光濾波效果。 請參閱圖7和圖8，其為本發明提供之週期性膜堆 1〇4(舰)18在參考波長為475nm，入射角分別為μ度和刃 度條件下之透射光譜圖。其中，實線為自然光之透射光譜 線’虛線為平行偏振光之透射光譜線，點劃線為垂直偏振 光之透射光譜線。對比圖7和圖3可知，本發明提供之週 期性膜堆m(册Γ在較大入射角（入射角為53度）時平 打偏振光與垂直偏振光透射光譜之偏移情況相較於現有膜 1 2W有了較大之改善。其次’在反射波長範圍内，本 么明提供之週期性膜1〇4(m/)18依然能保持較高之反射率， 有效地改善了現有膜堆2(呵8在較大入射角時反射波長範 圍内反射率升高之問題。對比圖7、圖8、圖3與圖4可知， 201003113 ‘本發明提供之週期性膜堆1〇4(册广在入射角為37度時之 平行偏振光與垂直偏振光透射光譜之偏移情況相較=^ Compared with the prior art, the membrane stack structure has a middle layer instead of the low refractive index ruthenium layer in the existing membrane stack structure, and the refractive index difference between the two refractive index film layers in the structure of the reduction membrane stack, age H 201003113 . The difference between the vertical polarization spectrum and the transmission parallel polarization spectrum is achieved to improve the transmission spectrum characteristics of the optical filter. [Embodiment] Please refer to Fig. 5, which is a schematic view of a membrane stack structure 10 provided by the present invention. The stack structure 10 includes a transparent substrate 102 and a periodic membrane stack 104 stacked thereon. The periodic structure of the periodic film stack 104 is an alternately laminated high refractive index film layer 106 and an intermediate refractive index layer 108. The periodic structure of the periodic film stack 104 can be expressed as (M)%, wherein Η represents a high refractive index film layer 106, Μ represents an intermediate refractive index film layer 104, and the ratio of coefficients in front of Η and Μ represents each The optical thickness ratio of the refractive index film layer, the superscript η represents the number of cycles of the periodic structure. The optical thickness of the high refractive index film layer 106 and the intermediate refractive index film layer 108 of the periodic film stack 104 are the same. The number of cycles of the periodic film stack 104 (//Μ)" In the present embodiment, the periodic film stack 104 has a period of 18, a transmission wavelength range of 480 nm to 670 nm, and a reflection wavelength range of 400 nm to 440 nm. The material of the transparent substrate 102 may be transparent glass or plastic material, such as colorless and highly transparent bismuth glass (B270) or slate glass. The high refractive index film layer 106 has a refractive index greater than 2.1, and the material thereof may be titanium dioxide or pentoxide. The intermediate refractive index film layer 108 has a refractive index ranging from 1.71 to 1.79 or 1.81 to 1.86, and the material may be an intermediate refractive index material M2 or M3 produced by Merck & Co., Germany. Embodiments 201003113 * In addition to the materials mentioned, other materials that can meet the refractive index requirements of each film layer can also be used, and each film layer is obtained by physical vapor deposition. See Figure 6, which is a periodic film. Heap 1〇4 (stomach) 18 in reference The transmission spectrum is 475nm and the incident angle is 45 degrees. The solid line is the transmission spectrum of natural light, the dotted line is the transmission spectrum of parallel polarized light, and the dotted line is the transmission spectrum of vertically polarized light. 6 and FIG. 2, the half-value wavelength difference between the parallel polarized spectrum line and the vertical polarization spectral line of the periodic film stack 104 is only 4 〇 nm. Compared with the structure, the present invention Providing a periodic film stack 1〇4 (the vast earth reduces the offset effect of the parallel polarization spectral line and the vertical polarization spectral line, so that the spectral characteristics of the natural light transmitted through the periodic film stack 104(//M) 18 are half The nonlinear non-smooth portion at the wavelength of the value is greatly improved, and the periodic film stack 1 〇 4 (the effect of the spectral filtering of the stomach is improved. Please refer to FIG. 7 and FIG. 8 , which is a periodic film provided by the present invention. The transmission spectrum of the stack 1〇4 (ship) 18 at a reference wavelength of 475 nm and the incident angle is μ degree and edge, respectively, where the solid line is the transmission spectrum line of natural light and the dotted line is the transmission spectrum line of parallel polarized light. , the dotted line is the transmission of vertically polarized light In comparison with FIG. 7 and FIG. 3, the periodic film stack m provided by the present invention provides a shift in the transmission spectrum of the flat polarized light and the vertically polarized light at a large incident angle (incident angle of 53 degrees). Compared with the existing film, 1 2W has a great improvement. Secondly, in the reflection wavelength range, the periodic film provided by the present invention 1〇4(m/)18 can still maintain a high reflectance, effectively improving The existing membrane stack 2 (the effect of the reflectance increase in the reflection wavelength range at a large incident angle). Compared with FIG. 7, FIG. 8, FIG. 3 and FIG. 4, 201003113 'The periodic membrane stack provided by the present invention 1〇 4 (Compared with the deviation of the parallel polarized light from the transmission spectrum of the vertically polarized light at an incident angle of 37 degrees =
膜堆々寧r有了較大之改善，且在入射角度由37至、53之 憂化祀圍内，本發明提供之週期性膜堆l(M =性隨入射歧之變化較小’可較大之入射角範圍= 較好之透射光譜特性。 相^财之技術’本㈣提供之㈣性料（伽)”通 率材:=射率材料替代現有膜層結構⑽”之低折射 f材枓’使传不同折射率膜層之折射率綠縮小從而有效 =減少分光遽波膜層在45度角入射時透射光譜之半值波長 處平行偏振光譜和垂直偏振光譜之偏移量，改善 =結構㈣”在較大人㈣時反射波長範_反射率下降之 且減少了分光滤波膜層在入射角變化時之透射光譜 ^戶:述’本發明確已符合發明專利之要件，遂依法 ，出，利申請。惟’以上所述者僅為本發明之較佳實施方 二敲自不能以此限制本案之申請專利範圍。舉凡熟悉本案 ^之人士援依本發明之精神所作之等效修飾或變化，皆 應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1為分光棱鏡之結構示意圖。 構二2為：射角為45度，參考波長為550nm時，膜堆結 構(/tt)之透射光譜圖。 圖3為入射角為53度，參考波長為483nm時，膜堆結 201003113 構(ffi)18之透射光譜圖。 圖4為入射角為37度，參考波長為483nm時，膜堆結 構（HL)18之透射光譜圖。 圖5為本發明提供之週期性膜堆（//M)"之結構示意圖。 圖6為入射角為45度，參考波長為475nm時，膜堆結 構（//M)18之透射光譜圖。 圖7為入射角為53度，參考波長為475nm時，膜堆結 構（//M)18之透射光譜圖。 圖8為入射角為37度，參考波長為475nm時，膜堆結 構(//M)18之透射光譜圖。 【主要元件符號說明】 分光棱鏡 1 膜堆結構 2 分光棱鏡上表面 4 鍍有膜堆結構之表面 3 分光棱鏡側面 5 膜堆結構 10 透明基底 102 週期性膜堆 104 高折射率膜層 106 中間折射率膜層 108 11The membrane stacking has a great improvement, and the periodic membrane stack provided by the present invention (the M = the change with the incident disparity is small) in the worrying angle of the incident angle from 37 to 53, Larger incident angle range = better transmission spectral characteristics. The technology of the phase of the wealth of the (four) provides (four) material (gamma)" rate material: = rate material replaces the existing film structure (10)" low refractive f The material 枓 'reduces the refractive index green of the different refractive index film layers to be effective = reduces the offset of the parallel polarization spectrum and the vertical polarization spectrum at the half-value wavelength of the transmission spectrum of the spectroscopic chopper film at an angle of 45 degrees. =Structure (4)" In the case of larger people (4), the reflection wavelength _ reflectance decreases and the transmission spectrum of the spectroscopic filter film layer changes at the incident angle is reduced. ^The present invention has indeed met the requirements of the invention patent, 遂law, However, the above description is only for the preferred embodiment of the present invention. It is not possible to limit the scope of the patent application in this case. Anyone familiar with the case ^ will be equivalently modified according to the spirit of the present invention. Or change, should be covered in the following application BRIEF DESCRIPTION OF THE DRAWINGS [Fig. 1 is a schematic diagram of the structure of a beam splitting prism. The structure 2 is: the transmission spectrum of the film stack structure (/tt) when the angle of incidence is 45 degrees and the reference wavelength is 550 nm. When the incident angle is 53 degrees and the reference wavelength is 483 nm, the transmission spectrum of the film stack 201003113 (ffi) 18 is shown. Figure 4 shows the transmission of the film stack structure (HL) 18 when the incident angle is 37 degrees and the reference wavelength is 483 nm. Fig. 5 is a schematic structural view of a periodic film stack (//M)" provided by the present invention. Fig. 6 is a film stack structure (//M) 18 when the incident angle is 45 degrees and the reference wavelength is 475 nm. Transmission spectrum Fig. 7 is a transmission spectrum of the film stack structure (//M) 18 when the incident angle is 53 degrees and the reference wavelength is 475 nm. Fig. 8 is the film stack when the incident angle is 37 degrees and the reference wavelength is 475 nm. Transmission spectrum of structure (//M) 18. [Description of main components] Spectroscopic prism 1 Membrane structure 2 Dividing prism upper surface 4 Surface coated with membrane stack structure 3 Spectroscopic prism side 5 Membrane stack structure 10 Transparent substrate 102 cycle Film stack 104 high refractive index film layer 106 intermediate refractive index film layer 108 11