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  2. Fresnel lens - Wikipedia

    en.wikipedia.org/wiki/Fresnel_lens

    The Fresnel lens reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections. An ideal Fresnel lens would have an infinite number of sections. In each section, the overall thickness is decreased compared to an equivalent simple lens.

  3. Fresnel equations - Wikipedia

    en.wikipedia.org/wiki/Fresnel_equations

    Fresnel equations. Partial transmission and reflection of a pulse travelling from a low to a high refractive index medium. At near-grazing incidence, media interfaces appear mirror-like especially due to reflection of the s polarization, despite being poor reflectors at normal incidence. Polarized sunglasses block the s polarization, greatly ...

  4. Catadioptric system - Wikipedia

    en.wikipedia.org/wiki/Catadioptric_system

    A catadioptric optical system is one where refraction and reflection are combined in an optical system, usually via lenses ( dioptrics) and curved mirrors ( catoptrics ). Catadioptric combinations are used in focusing systems such as searchlights, headlamps, early lighthouse focusing systems, optical telescopes, microscopes, and telephoto ...

  5. List of medical roots, suffixes and prefixes - Wikipedia

    en.wikipedia.org/wiki/List_of_medical_roots...

    This is a list of roots, suffixes, and prefixes used in medical terminology, their meanings, and their etymologies. Most of them are combining forms in Neo-Latin and hence international scientific vocabulary. There are a few general rules about how they combine.

  6. Fresnel integral - Wikipedia

    en.wikipedia.org/wiki/Fresnel_integral

    The sector contour used to calculate the limits of the Fresnel integrals. This can be derived with any one of several methods. One of them [5] uses a contour integral of the function around the boundary of the sector-shaped region in the complex plane formed by the positive x-axis, the bisector of the first quadrant y = x with x ≥ 0, and a circular arc of radius R centered at the origin.

  7. Total internal reflection - Wikipedia

    en.wikipedia.org/wiki/Total_internal_reflection

    Total internal reflection. In physics, total internal reflection ( TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium.

  8. Numerical aperture - Wikipedia

    en.wikipedia.org/wiki/Numerical_aperture

    In microscopy, NA is important because it indicates the resolving power of a lens. The size of the finest detail that can be resolved (the resolution) is proportional to ⁠ λ / 2NA ⁠, where λ is the wavelength of the light. A lens with a larger numerical aperture will be able to visualize finer details than a lens with a smaller numerical ...

  9. Fresnel lantern - Wikipedia

    en.wikipedia.org/wiki/Fresnel_lantern

    A Fresnel with the lens open to show the ridges. There is no lamp in the instrument. A Fresnel lantern (pronounced frəˈnɛl or fruh-nel) is a common lantern used in theatre that employs a Fresnel lens to wash light over an area of the stage. The lens produces a wider, soft-edged beam than a spotlight or key light, and is commonly used for ...