ref "Engineering Optics" 4th Edition Yu Daoyin
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1. Basic laws of geometric optics
Refractive index: n = c / vn=c/vn=c / v , the speed of light vvof the mediumv relative vacuum speed of lightccthe degree of slowing down of c
The law of straight line propagation of light
In an isotropic homogeneous medium, light travels in straight lines
- Light propagation encounters obstacles (holes/slits) on the order of wavelengths, diffraction occurs, and the conditions for the establishment of the law are violated
The law of independent propagation of light
Lights emitted by different light sources meet at a certain point in space without affecting each other, and each beam propagates independently
- Two beams of light are emitted from the same monochromatic point light source, and travel through different paths to meet at a certain point in space, interfere, and destroy the established conditions of the law
law of reflection
I ′ ′ = − I I''=-I I''=−I
total reflection
- Optical density -> optical thinning , incident angle> critical angle
law of refraction
n ′ sin I ′ = n sin I n'\sin I'=n\sin I n'sinI'=nsinI
Reversibility of the optical path
Fermat's principle (the principle of the shortest optical path)
Light travels from one point to another, no matter how many times it is reflected and refracted, the optical path is an extreme value
Marius' law
In an isotropic homogeneous medium : the light and the wavefront are orthogonal , and the point optical path corresponding to the incident surface and the outgoing wavefront is unchanged
Fermat's Principle, Marius' Law <=> Line, Independence, Reflection, Refraction
2. Perfect imaging conditions
- When the incoming wave is a spherical wave, the outgoing wave is also a spherical wave
- When the incident light is a concentric beam, the outgoing light is also a concentric beam
- The optical path of any two optical paths between the object point and the image point is equal
3. Apply the notation rules of optics
4. Single refraction spherical light path calculation
5. Single-refractive surface imaging
- Vertical magnification
β = y ′ y = nn ′ l ′ l \beta=\frac{y'}{y}=\frac{n}{n'}\frac{l'}{l}b=YY′=n'nll′- Like size: object size
- β > 0 \beta>0b>0 : Form a positive image, the object image is on the same side, the virtual and the real are opposite
- ∣ β > 1 ∣ |\beta>1|∣ β>1∣ : as an enlarged image
- Axial magnification
α = dl ′ dl = n ′ n β 2 \alpha=\frac{dl'}{dl}=\frac{n'}{n}\beta^2a=dldl′=nn′b2- Slight movement of the conjugate image point: Slight movement of the object point on the axis
- 角手机率
γ = u ′ u = nn ′ 1 β \gamma=\frac{u'}{u}=\frac{n}{n'}\frac{1}{\beta}c=inin′=n'nb1- Conjugate ray ∠ \angle∠ optical axis: incident ray∠ \angle∠Optical axis
- Lach invariant
J = n ′ u ′ y ′ = nuy J=n'u'y'=nuyJ=n′ in′ and'=u y _- The product of the size of the object x the aperture angle of the imaging beam x the refractive index of the medium does not change
- Refraction
n ′ l ′ − nl = n ′ − nr \frac{n'}{l'}-\frac{n}{l}=\frac{n'-n}{r}l'n′−ln=rn'−n - Reflection
n ′ = − n n'=-nn'=−n
1 l ′ + 1 l = 2 r \frac{1}{l'}+\frac{1}{l}=\frac{2}{r} l'1+l1=r2