Light Scatterind Flashcards
Scattering of light is caused due to the ____________ in a medium
In-homogeneities
Defuse diffraction
Air and medium with high index
What are the two types of scattering?
Incoherent
Coherent
Conditions for incoherent scattering
White light
Particles far apart
Incoherent scattering depends on
Size of particles
Distance between particles
Strength of interaction
What determines the strength of the interaction in incoherent light scattering?
Refractive index and absoprtion strength
When the scattering particles are smaller than the wavelength
Rayleigh scattering
What does rayleigh scattering profile show?
Forward and backward scatter (scatter in all directions)
Rayleigh has a strong _________ dependence
Wavelength
What kind of wavelength scatters more in rayleigh scattering?
Shorter, blue
Rayleigh scattering is an ____________, as the scattered photons energy do not change.
Elastic scattering
Light going to a denser medium changes the _______
Wavelength
For rayleigh scattering, the intensity of the scattering blue light it _______ times than that of the scattered red light
3.3
How do you calculate relative scattering intensity?
(Lambda1/lamda2)^4
How much brighter is LED than sodium light?
3x
The bluer the light, the more the light scatters and the larger the area of the ______
Glare
Downside of LED?
Affects astronomical observations, and causes harmful effects on he wild plants, and animal population (light pollution)
Photopic sensitivity
Day time sensitivity, when rods are sensitive
What does blue light disrupt?
Circadian rhythm, disrupts melatonin
Mesopic vision
Dawn/dusk
Rods and cones become active
Scotopic sensitivity
Peak sensitivity at about 500nm
When the scattering particles are larger than the wavelength of light
Mie scattering
What are the dominant causes of mie scattering?
Geometrical optics process of reflection and refraction are the dominant causes of the mie scattering
Scattering profile of mie scattering
Stronger forward scattering
Mie scattering theory applies for particles to both ________ and _______
Absorb and scatter, rayleigh is only scatter
Techniques based on mie scattering theory are used in several studies in the understanding of
Optical properties of biological tissues like skin, brain, bone, other soft tissues, other fibrous tissues and fatty tissues, and even blood cells
What are some examples of Rayleigh’s scattering
Bluish smoke from fire and cigarette
Why does cigarette smoke appear blue but when its exhaled, becomes white?
Its Rayleigh scattering first, then when it is inhaled, it mixes with the moisture particles and becomes mie scattering
The more the light is scattered, the less the wavelength dependence of the ________
Scattered intensity
