翻訳と辞書 Words near each other ・ Compound of two great retrosnub icosidodecahedra ・ Compound of two great snub icosidodecahedra ・ Compound of two icosahedra ・ Compound of two inverted snub dodecadodecahedra ・ Compound of two small stellated dodecahedra ・ Compound of two snub cubes ・ Compound of two snub dodecadodecahedra ・ Compound of two snub dodecahedra ・ Compound of two snub icosidodecadodecahedra ・ Compound of two truncated tetrahedra ・ Compound option ・ Compound pier ・ Compound Poisson distribution ・ Compound Poisson process ・ Compound presentation ・ Compound prism ・ Compound probability distribution ・ Compound refractive lens ・ Compound S ・ Compound semiconductor ・ Compound shutter ・ Compound spirit of ether ・ Compound squeeze ・ Compound steam engine ・ Compound subject ・ Compound TCP ・ Compound term processing ・ Compound turbine ・ Compound verb ・ Compounding Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Compound prism ： ウィキペディア英語版 Compound prism A compound prism is a set of multiple triangular prism elements placed in contact, and often cemented together to form a solid assembly.〔John Browning, "Note on the use of compound prisms," ''MNRAS'' 31: 203-205 (1871).〕 The use of multiple elements gives several advantages to an optical designer:〔Nathan Hagen and Tomasz S. Tkaczyk, "(Compound prism design principles, I )," ''Appl. Opt.'' 50: 4998-5011 (2011).〕 * One can achieve spectral dispersion without causing the deviation of the beam at the design wavelength. Thus, light at the design wavelength which enters at an angle $\backslash theta\_0$ with respect to the optical axis, exits the prism at the same angle with respect to the same axis. This kind of effect is often called "direct vision dispersion" or "nondeviating dispersion".〔Charles G. Abbott and Frederick E. Fowle, Jr., "A prism of uniform dispersion," ''Astrophys. J.'' 11: 135-139 (1900).〕 * One can achieve deviation of the incident beam while also greatly reducing the dispersion introduced into the beam: an achromatic deflecting prism. This effect is used in beam steering.〔Bradley D. Duncan, Philip J. Bos, and Vassili Sergan, "Wide-angle achromatic prism beam steering for infrared countermeasure applications," ''Opt. Eng'' 42: 1038-1047 (2003).〕〔Zhilin Hu and Andrew M. Rollins, "Fourier domain optical coherence tomography with a linear-in-wavenumber spectrometer," ''Opt. Lett.'' 32: 3525-3527 (2007).〕 * One can tune the prism dispersion to achieve greater dispersion linearity or to achieve higher-order dispersion effects. ==Doublet== The simplest compound prism is a doublet, consisting of two elements in contact, as shown in the figure at right. A ray of light passing through the prism is refracted at the first air-glass interface, again at the interface between the two glasses, and a final time at the exiting glass-air interface. The deviation angle $\backslash delta$ of the ray is given by the difference in ray angle between the incident ray and the exiting ray: $\backslash delta\; =\; \backslash theta\_0\; -\; \backslash theta\_4$. While one can produce direct vision dispersion from doublet prisms, there is typically significant displacement of the beam (shown as a separation between the two dashed horizontal lines in the ''y'' direction). Mathematically, one can calculate $\backslash delta$ by concatenating the Snell's law equations at each interface,〔 :$$ \begin \theta_1 &= \theta_0 - \beta_1 &\theta_3 &= \theta'_2 - \alpha_2 \\ \theta'_1 &= \arcsin (\tfrac \, \sin \theta_1) \quad &\theta'_3 &= \arcsin (n_2 \, \sin \theta_3) \\ \theta_2 &= \theta'_1 - \alpha_1 &\theta_4 &= \theta'_3 + \tfrac \alpha_2 \\ \theta'_2 &= \arcsin (\tfrac \, \sin \theta_2) \end so that the deviation angle is a nonlinear function of the glass refractive indices $n\_1\; (\backslash lambda)$ and $n\_2\; (\backslash lambda)$, the prism elements' apex angles $\backslash alpha\_1$ and $\backslash alpha\_2$, and the angle of incidence $\backslash theta\_0$ of the ray. Note that $\backslash alpha\_i$ indicates that the prism is inverted (the apex points downward). If the angle of incidence $\backslash theta\_0$ and prism apex angle $\backslash alpha$ are both small, then $\backslash sin\; \backslash theta\; \backslash approx\; \backslash theta$ and $\backslash text\; (x)\; \backslash approx\; x$, so that the nonlinear equation in the deviation angle $\backslash delta$ can be approximated by the linear form :$$ \delta (\lambda) = \big(n_1 (\lambda - 1 \big ) \alpha_1 + \big(n_2 (\lambda) - 1 \big ) \alpha_2 \ . (See also Prism deviation angle and dispersion.) If we further assume that the wavelength dependence to the refractive index is approximately linear, then the dispersion can be written as :$$ \Delta = \frac + \frac \ , where $\backslash delta\_i$ and $V\_i$ are the dispersion and Abbe number of element $i$ within the compound prism, $V\_i\; =\; (\backslash bar\; -\; 1)\; /\; (n\_F\; -\; n\_C)$. The central wavelength of the spectrum is denoted $\backslash bar$. Doublet prisms are often used for direct-vision dispersion. In order to design such a prism, we let $\backslash bar\; =\; 0$, and simultaneously solving equations $\backslash delta$ and $\backslash Delta$ gives :$$ \delta_1 (\bar) = - \delta_2 (\bar) = -\Delta \Big( \frac - \frac \Big)^ \ , from which one can obtain the element apex angles $\backslash alpha\_1$ and $\backslash alpha\_2$ from the mean refractive indices of the glasses chosen: :$$ \begin \alpha_1 &= \frac \Big( \frac - \frac \Big)^ \ , \\ \alpha_2 &= \frac \Big( \frac - \frac \Big)^ \ . \end Note that this formula is only accurate under the small angle approximation. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Compound prism」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.