Optics
6 terms
Acceptance Angle
Optics
Degrees (°)
The maximum angle relative to the fiber axis at which incident light can enter the fiber core and undergo total internal reflection.
θ_a = arcsin(NA) = arcsin(√(n1² - n2²))
Accommodation of the Eye
Optics
Diopters (D)
The automatic adjustment process by which ciliary muscles alter crystalline lens focal length to focus objects at varying distances onto the retina.
Power range ΔP = P_near - P_far
Angle of Deviation
Optics
Degrees (°)
The angle between the direction of an incident light ray entering an optical element (like a prism) and its emerging direction.
δ = i1 + i2 - A
Astigmatism
Optics
Diopters (D)
A visual defect caused by non-spherical, asymmetric curvature of the cornea or lens, preventing rays in different planes from focusing at a single point.
Power difference = P_vertical - P_horizontal
Astronomical Telescope
Optics
Dimensionless (×)
A refracting optical instrument consisting of a long-focal-length objective lens and short-focal-length eyepiece used to observe distant celestial bodies.
M = -f_obj / f_eye, Tube Length L = f_obj + f_eye
Attenuation
Optics
dB/km
The loss of optical power or signal strength as light propagates through a medium or optical fiber.
α = (10 / L) log10(P_in / P_out)