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  2. Sagitta (geometry) - Wikipedia

    en.wikipedia.org/wiki/Sagitta_(geometry)

    When the sagitta is small in comparison to the radius, it may be approximated by the formula [2] s ≈ l 2 8 r . {\displaystyle s\approx {\frac {l^{2}}{8r}}.} Alternatively, if the sagitta is small and the sagitta, radius, and chord length are known, they may be used to estimate the arc length by the formula

  3. Fresnel equations - Wikipedia

    en.wikipedia.org/wiki/Fresnel_equations

    Fresnel equations calculator FreeSnell – Free software computes the optical properties of multilayer materials. Thinfilm – Web interface for calculating optical properties of thin films and multilayer materials (reflection & transmission coefficients, ellipsometric parameters Psi & Delta).

  4. Sagitta (optics) - Wikipedia

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

    Deep blue ray refers the radius of curvature and the red line segment is the sagitta of the curve (black).. In optics and especially telescope making, sagitta or sag is a measure of the glass removed to yield an optical curve.

  5. Ray transfer matrix analysis - Wikipedia

    en.wikipedia.org/wiki/Ray_transfer_matrix_analysis

    Each optical element (surface, interface, mirror, or beam travel) is described by a 2 × 2 ray transfer matrix which operates on a vector describing an incoming light ray to calculate the outgoing ray. Multiplication of the successive matrices thus yields a concise ray transfer matrix describing the entire optical system.

  6. Focal length - Wikipedia

    en.wikipedia.org/wiki/Focal_length

    The focal point F and focal length f of a positive (convex) lens, a negative (concave) lens, a concave mirror, and a convex mirror.. The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power.

  7. Conic constant - Wikipedia

    en.wikipedia.org/wiki/Conic_constant

    The equation for a conic section with apex at the origin and tangent to the y axis is + (+) = alternately = + (+) where R is the radius of curvature at x = 0. This formulation is used in geometric optics to specify oblate elliptical ( K > 0 ), spherical ( K = 0 ), prolate elliptical ( 0 > K > −1 ), parabolic ( K = −1 ), and hyperbolic ( K ...

  8. Numerical aperture - Wikipedia

    en.wikipedia.org/wiki/Numerical_aperture

    Instead, the angular aperture of a lens (or an imaging mirror) is expressed by the f-number, written f /N, where N is the f-number given by the ratio of the focal length f to the diameter of the entrance pupil D: =. This ratio is related to the image-space numerical aperture when the lens is focused at infinity. [3]

  9. Reflection coefficient - Wikipedia

    en.wikipedia.org/wiki/Reflection_coefficient

    In telecommunications and transmission line theory, the reflection coefficient is the ratio of the complex amplitude of the reflected wave to that of the incident wave. The voltage and current at any point along a transmission line can always be resolved into forward and reflected traveling waves given a specified reference impedance Z 0.