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29 Cards in this Set
- Front
- Back
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What happens to light every time it hits a surface?
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4% of it is lost because of reflection and refraction.
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snell's law
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n1sin(a)=n2sin(b)
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index of refraction n = ?
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speed of light in vacuum/ speed of light in medium
c/v1 |
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what is the critical angle?
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critical angle is the angle needed to determine if total internal reflection will occur.
it is: sin(critical angle) = nB/Na where Nb and Na are indexes of refraction total internal reflection occurs for angles higher than critical angle. |
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Numerical aparture
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Na= n sin(a)
(light gathering capacity) sin(a) is half angle of cone of light n is index of refraction of medium |
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How to determine if a virtual or real image is formed?
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a real image is formed when n1<n2 with a ( shaped lens
a virtual image is formed when n1>n2 in a ) shaped lens (N2-N1)/r = (n1/p) + (n2/q) p- distance btw object and interface q distance between image and interface (if negative it is a virtual image) r- radius of curvature of lens |
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What is the thin lens equation and what does it tell you?
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(1/f) = 1/p + 1/q
Tells you about the position of the object and the magnification of the image f is the focal length p is distance from object to center of lens q is the distance from the lens to the image. |
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spot size
and area |
f(wavelength)/d
d is diameter of raw bean f is focal length area = (∏(ss)^2)/4 |
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What are the two ways to characterize light in terms of wavelength?
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spacialy: (x position is on the x axis)
k vector = 2pi/wavelength wave number: k = 1/wavelength tmporally (time is on the x axis) angular frequency = 2pi/period frequency= 1/period |
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what is frequency in terms of wavelenths and speed of light?
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v= c/wavelength
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what is c
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2.998 x 10^8 m/s
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energy of a photon?
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E= hv
E= hc/wavelength h= 6.626 x 10^-34 Js |
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what is the range of visible light?
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350 - 720 nm
violet red |
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what are the properties of lasers?
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columnated - rats are parallel
coherent- all rays are in phase monochromatic |
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what is the intensity of a laser? (I)
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power/area
same as irradience power can be average or peak |
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what is raleigh scattering?
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re-emitted wavelength = incident wavelength
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what is raman scattering?
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re-emited wavelength = incident wavelength
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peak power of a laser?
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Pk = Energy/ period
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fluence (focused energy of a laser)
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E/area
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energy per pulse of pulse laser?
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P avg/ rep. rate
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Lambert-Beer law? what is it and what does it decribe
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change of intenstiy of light as it goes through a medium:
I(Z) = Iinitial e^-(Beta)z z is thickness of medium or distance traveled through medium Beta = μa + μs μa= absorbtion coefficient μs = scattering coefficiient |
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types of microscopes?
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Some types of microscopes
Brightfield/Transillumination (absorption) Phase contrast (scattering/phase retardation) Differential Interference Contrast scattering/refractive index gradient) Fluorescence Confocal (depth resolution; reflectance/fluorescence) Multi-photon fluorescence (depth resolution) Second Harmonic Generation (depth resolution; scattering) |
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what is resolution
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the min distance between two objects in which the two objects can be distinguished as sepatare
r= .61λ/Na |
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percent contrast?
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% contrast = [(Ib/Is)/Ib) x 100
Ib intensity of background Is intensity of sample |
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trans illumination
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illumination and imging on diff sides of specimine
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epi illumination
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illumination and imaging on same side of specimen
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resolution range of light microscope?
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.1 microms - 1mm
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resolution range of Electron microscope?
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1.1 angstrom to 100 microns
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magnification
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M = -q/p
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