Optics Inference 2

Question 1

Anti-reflective film on glass surface such that the front and back surface reflections
_______________interfere

Answer 1

destructively

Question 2

Magnesium fluoride coating reduces the
front surface reflection from _____to ______

Note that to reduce the back surface reflection,
R2
, a _____must be applied to the back
surface.

Answer 2

4.3% to 1.5%.

thin film

Question 3

A magnesium fluoride coating will reduce the reflection, but to reduce it further requires
a _________

Answer 3

multilayer coating

Question 4

Advantages of Anti Reflection to Patients

• See _____more crisply
• Environment appears _____
• ______benefit

Answer 4

details
brighter
Cosmetic

Question 5

Disadvantages of AR coating:
• Exaggerated appearance of \_\_\_\_\_\_
• Elimination of reflection by multi layer AR coating
is not cosmetically beneficial
it gives a \_\_\_\_\_\_ apperance

Answer 5

dirt.

dead gray

Question 6

The Solution to the Dead gray apperance given by the multilayer coating is ____

Answer 6

residual color

Question 7

: is a high transmittance narrow band
filter.
.

Answer 7

Interference filter

Question 8

Interference filter transmits by_______ interference while reflecting
all other _________

Answer 8

constructive

wavelengths

Question 9

Types of filters:

__________ filters that only permit
longer wavelengths to pass through

Answer 9

Long-pass interference

Question 10

Types of filters:

_________ filters that only permit
shorter wavelengths to pass through

Answer 10

Short-pass interference

Question 11

Types of filters:

________ filters that only permit a
certain wavelength band to pass through

Answer 11

Band-pass interference

Question 12

_______– reflect IR and
transmit visible
•

Answer 12

Hot mirror

Question 13

_________ – reflect visible and

transmit IR

Answer 13

Cold mirror

Question 14

________ is a biological mirror that reflects light

which passed through rods & cones.

Answer 14

tapetum lucidum

Question 15

tapetum lucidum

• The biological mirror consists of a multilayer stack of films
much like the AR coatings on spectacles. However, a
critical difference is that the OPL between reflections is_____
rather than ______. Thus ______, rather than _______
interference occurs.

Answer 15

λ

λ/2
constructive

destructive

Question 16

Young’s double slit Or Thin Film Interference?

Interference by division of Wavefront

Answer 16

Y

Question 17

Young’s double slit Or Thin Film Interference?

Interference by division of Amplitude

Answer 17

T

Question 18

Young’s double slit Or Thin Film Interference?

Polychromatic light

Answer 18

T

Question 19

Young’s double slit Or Thin Film Interference?

Mutually Coherent source

Answer 19

Y

Question 20

Young’s double slit Or Thin Film Interference?

Monochromatic light

Answer 20

Y

Question 21

Young’s double slit Or Thin Film Interference?

Incoherent source

Answer 21

T

Question 22

Young’s double slit Or Thin Film Interference?

Two wave interference

Answer 22

Y

Question 23

Young’s double slit Or Thin Film Interference?

Path difference
dsinθ = mλ

Answer 23

Y

Question 24

Young’s double slit Or Thin Film Interference?

Obeys law of conservation of energy
(i.e) redistribution of energy

Answer 24

both

Question 25

Young’s double slit Or Thin Film Interference?

Multiple wave interference (wave effect)

Answer 25

T

Question 26

Young’s double slit Or Thin Film Interference?

Path difference (2t = mλ
thickness, t=λ/4n)
Phase change
Material on both sides

Answer 26

T

Question 27

Instruments based on the principle of interference of light are known as_______

Answer 27

interferometers

Question 28

__________ are high sensitive precision metrology instruments. Accuracy & precision to scale of mm and nm

Answer 28

interferometers

Question 29

It has been used for a long time in the
astronomical telescopes, optics industry,
and recently in biological imaging.

Answer 29

Interferometers

Question 30

Interferometers are used to determine…
• Optical testing like surface _____,______,____
• Wavelength of ______
• Thickness of ____ strips

Answer 30

roughness, flatness, curvature, etc.,

light

thin

Question 31

Interferometers are used to determine…

• Optical aberrations of:

• _____ displacements
• Refractive index changes
• spectroscopy

Answer 31

of lenses, glasses etc.

small

Question 32

Shearing
Interferometers
can be used to
determine if a
coherent beam
of light is
\_\_\_\_\_\_\_\_

Answer 32

collimated.

Question 33

__________shows the design and manufacturing defects before thousands of lenses are made

Answer 33

Surface profile

Question 34

Optical coherence tomography (OCT) Corneal and Retinal Imaging
is An imaging technology based on :

Answer 34

Michelson Interferometry

Question 35

is a noninvasive, interferometric imaging modality that provides significantly higher
sensitivity and axial resolution
than the conventional imaging systems

Answer 35

Optical
coherence
tomography

Question 36

______is useful in finding abnormalities in the retinal
layers non invasively, which the fundus camera may not
have the potential and resolution to detect.

Answer 36

Optical coherence tomography

OCT

Question 37

\_\_\_\_\_\_Interferometer :light from the two
telescopes are
brought
together in an
image plane to
interfere, just like
Young’s two-slit
experiment.

Answer 37

Michelson Interferometer

Question 38

\_\_\_\_\_\_\_\_\_\_\_\_\_ allow
astronomers to reconstruct
a detailed picture of the
inner disc of matter around
a young star.

Answer 38

Michelson Interferometer

Question 39

These waveforms show the detection of gravitational
waves from two merging black holes several light years
away as predicted by Albert Einstein’s general theory of
relativity

Answer 39

LIGO: Laser Interferometer Gravitational wave Observatory