turning Point Questions Flashcards
Diffraction is a change in direction of propagation due to
Edge phenomenon
Fresnel, secondary wavelets undergo mutual interference, true or false
True
Constructive interference in a single slit diffraction
asin(theta)=m (lambda)
A=slit width
What is the type of diffraction, if the source of light and the screen are at finite distance from the diffraction aperture?
Fresnel
In the single slit diffraction, when the aperture size ‘a’ decreases, what happens to the diffraction pattern?
Spreads out
What os the type of diffraction, if the source of light and the screen are at a finite distance from the diffraction aperture
Fresnel diffraction
The smallest letters that a person with 20/2 snellen acuity can resolve have detail that subtends at angle of ____
1’
What happens to diffraction image point in a phase plate when the alternate zones are phase shifted by 180 degrees?
Brighter
When a diffractive structure (phase plate) is embedded on one side of the refractive lens, the lens is called
Hybrid
In the diffractive multifocal lens, when m=0 the power of the lens is
Zero
In a diffractive multifocal lens, the first order diffraction generates the _____ power
Add power
Wearing multifocal lens causes some patients see shadows formed onto their retina. This condition is called _____
Negative dysphotopsia
The strength of the iridescence in a mollusk shell is due to _____ and _______
Groove density and surface quality
Fresnel’ lans increases the luminosity of the lighthouse lamp by a factor of _____
4
The energy allocation, in diffractive multifocal lens, between 0th order and 1st order is known as _____
Diffraction efficiency
What causes the interference pattern to form 3d holography image
Phase difference
While using a coherent source to view a recorded holography image, which of the diffraction orders does one view the image?
-1 order
In a typical human eye when the pupil size increases, which one of the following will increasingly affect vision
Aberration
Diffraction is a change in direction due to
Edge phenomenon
What equation is for constructive interference in a single slit diffraction
Asin(theta)=m(lambda)
Which of the scattering will happen when the particles are smaller than the wavelength of the light
Rayleigh
What is the scattering profile of Mie scattering
Mostly forward
Bluer the light, more the light scatter
True
For a healthy non-cataractous eye, the intraocular scatter increases by 2x at the age of ____ compared to young eyes
65
In the blue/blue-green eyes, intraocular scatter is caused by pigmentations in the scleral wall, iris and ________
Fundus
Which of the following refractive surgery techniques causes an increase of intraocular scatter by a factor of 4?
RK
Corneal transmittance is dependent on
Wavelength
When wave 1 and wave 2 are in phase, but wave 1 travels an extra distance ( or path difference) equal to 1 wavelength, then this interference is called
Constructive interference
Condition for destructive interference is when the path difference between two waves is equal to (m is an integer, n is the refractive index, lambda is the wavelength)
(M+1/2)/lambda
In the condition for forming bright fringes, dsin(theta)=mlambda, ‘d’ represents the distance between the 2 slits and the screen
False
A He-Ne laser beam (lambda=632.8nm) is incident on double slits of separation 0.8mm. On a screen located 6m from the slits, how far is the third order maximum from the center of the interference pattern?
14.2mm
Y=m(lambda)L/d
Two conditions for getting an interference fringe in youngs double slit experiment is
Monochromatic light and mutual coherence
Thin film interference is based on the division of amplitude, true or false
True
Which is commonly used single layer anti reflection coating material?
Magnesium fluoride
Single layer anti reflection coating reduces light reflection from 4.3% to about _______
1.5%
How much does a multilayer anti reflection thin film coating reduce the light reflection to about ?
0.5%
The minimum thickness of an anti reflecting thin film on glass is _______ of the wavelength in the thin film
Quarter
Diffraction is a change in direction of propagation due to
Edge phenomenon
According to fresnel, whom expanded on huygen’s principle, proposed that that the secondary wavelets would undergo mutual interference
True
What is the condition for constructive interference in a single slit diffraction
Asin(theta)=m(lambda)
In the single slit diffraction, when the aperture size ‘a’ decreases, what happens to the diffraction pattern
Spread out
What is the type of diffraction, if the source of light and the screen are at a finite distance from the diffraction aperture
Fresnel diffraction
The smallest letters that a person with 20/40 acuity can resolve have a detail that subtends at angle of ____
2’
An optical device that blocks alternate zones is called
Zone plate
What happens to diffraction image point in a pjhase plate when the alternate zones are phase shifted by 180
Brighter
Incoherent scattering depends on what two conditions?
Particle size and distance between two particle ( it should be greater than coherence of the light)
When the particles are smaller than wavelength of light, what type of scatterin
Rayleigh
What is the scattering profile of rayleigh
All directions
Shorter wavelength scatters more light, true or false
True, blue
Corneal transmittance is dependent upon
Wavelength
What is the effect of light transmission to blue rims for red light
1% because of absence of melanin
0.2% for green light
What is the 3rd component for blue and green eyes in scatter other than scleral wall and iris?
Fundus
As you age for a healthy non cataractous eye, what is the increase in scatter for age 77?
3x
What percentage of horizontally polarizaed light gets transmitted if a vertically polarized filter is tilted 5 degrees?
Cos^2(theta)
Cos^2(5)
8%
Make sure to change to radians in calculator!!
For light in air incident on high index plastic of 1.66 refractive index, what is the incident angle of polarization
Brewsters angle
Tan(theta)=n2/n1
53.93 degrees
The sunlight glare can pass through a polarized filter when the transmission axis is _______
Horizontal
-if you hold it vertical, you will stop the sunlight scatter
The waggle dance of the bee communicates the direction of food and _____
Location
Formed dichroism is based on specific property of material which is ______
Structure
When light travels in birefringent material, a relative delay between transmission is called
Phase retardation
What is the slow ray in polarization called
Extraordinary ray
What is the fast ray in polarization called
Ordinary ray
Due to birefringence of cornea and lens, it changes from linear polarization to ______
Elliptical
Haidenger’s brush apparatus could be used to diagnose mblyopia due to what
Eccentric target
