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  2. Surface imperfections (optics) - Wikipedia

    en.wikipedia.org/wiki/Surface_imperfections_(optics)

    David Aikens, director of Optics and Electro-Optics Standards Council, [9] presented a recommended conversion chart that preserves the level of quality control, or percent fall, in ISO scratch & dig testing versus the military standard. For example 5/2x0.40; L 3 x0.010 is a statistically-equivalent standard to 60-40 of the strict military ...

  3. Etendue - Wikipedia

    en.wikipedia.org/wiki/Etendue

    Etendue for a differential surface element in 2D (left) and 3D (right).. An infinitesimal surface element, dS, with normal n S is immersed in a medium of refractive index n.The surface is crossed by (or emits) light confined to a solid angle, dΩ, at an angle θ with the normal n S.

  4. Polarization mode dispersion - Wikipedia

    en.wikipedia.org/wiki/Polarization_mode_dispersion

    Polarization mode dispersion (PMD) is a form of modal dispersion where two different polarizations of light in a waveguide, which normally travel at the same speed, travel at different speeds due to random imperfections and asymmetries, causing random spreading of optical pulses.

  5. Cardinal point (optics) - Wikipedia

    en.wikipedia.org/wiki/Cardinal_point_(optics)

    In optics, surface vertices are the points where each optical surface crosses the optical axis. They are important primarily because they are physically measurable parameters for the optical element positions, and so the positions of the cardinal points of the optical system must be known with respect to the surface vertices to describe the system.

  6. Waveguide (optics) - Wikipedia

    en.wikipedia.org/wiki/Waveguide_(optics)

    The basic principles behind optical waveguides can be described using the concepts of geometrical or ray optics, as illustrated in the diagram. Light passing into a medium with higher refractive index bends toward the normal by the process of refraction (Figure a.). Take, for example, light passing from air into glass.

  7. Optical manufacturing and testing - Wikipedia

    en.wikipedia.org/wiki/Optical_manufacturing_and...

    Direct surface surveying (no intervening optics, for example Foucault knife-edge test, Ronchi test, Caustic test) Auxiliary optics (null correctors, computer-generated holograms, etc.) Interferometric testing; The Fizeau interferometer is the standard type of interferometer that is used in optical fabrication. [12]

  8. Zone plate - Wikipedia

    en.wikipedia.org/wiki/Zone_plate

    Example of an image taken with zone plate optics. Zone plates are also used in photography in place of a lens or pinhole for a glowing, soft-focus image. One advantage over pinholes (aside from the unique, fuzzy look achieved with zone plates) is that the transparent area is larger than that of a comparable pinhole.

  9. Photometry (optics) - Wikipedia

    en.wikipedia.org/wiki/Photometry_(optics)

    Photometry is a branch of optics that deals with measuring light in terms of its perceived brightness to the human eye. [1] It is concerned with quantifying the amount of light that is emitted, transmitted, or received by an object or a system.