Optics Inference 2 Flashcards
Anti-reflective film on glass surface such that the front and back surface reflections
_______________interfere
destructively
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.
4.3% to 1.5%.
thin film
A magnesium fluoride coating will reduce the reflection, but to reduce it further requires
a _________
multilayer coating
Advantages of Anti Reflection to Patients
- See _____more crisply
- Environment appears _____
- ______benefit
details
brighter
Cosmetic
Disadvantages of AR coating: • Exaggerated appearance of \_\_\_\_\_\_ • Elimination of reflection by multi layer AR coating is not cosmetically beneficial it gives a \_\_\_\_\_\_ apperance
dirt.
dead gray
The Solution to the Dead gray apperance given by the multilayer coating is ____
residual color
: is a high transmittance narrow band
filter.
.
Interference filter
Interference filter transmits by_______ interference while reflecting
all other _________
constructive
wavelengths
Types of filters:
__________ filters that only permit
longer wavelengths to pass through
Long-pass interference
Types of filters:
_________ filters that only permit
shorter wavelengths to pass through
Short-pass interference
Types of filters:
________ filters that only permit a
certain wavelength band to pass through
Band-pass interference
_______– reflect IR and
transmit visible
•
Hot mirror
_________ – reflect visible and
transmit IR
Cold mirror
________ is a biological mirror that reflects light
which passed through rods & cones.
tapetum lucidum
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.
λ
λ/2
constructive
destructive
Young’s double slit Or Thin Film Interference?
Interference by division of Wavefront
Y
Young’s double slit Or Thin Film Interference?
Interference by division of Amplitude
T
Young’s double slit Or Thin Film Interference?
Polychromatic light
T
Young’s double slit Or Thin Film Interference?
Mutually Coherent source
Y
Young’s double slit Or Thin Film Interference?
Monochromatic light
Y
Young’s double slit Or Thin Film Interference?
Incoherent source
T
Young’s double slit Or Thin Film Interference?
Two wave interference
Y
Young’s double slit Or Thin Film Interference?
Path difference
dsinθ = mλ
Y
Young’s double slit Or Thin Film Interference?
Obeys law of conservation of energy
(i.e) redistribution of energy
both
Young’s double slit Or Thin Film Interference?
Multiple wave interference (wave effect)
T
Young’s double slit Or Thin Film Interference?
Path difference (2t = mλ
thickness, t=λ/4n)
Phase change
Material on both sides
T
Instruments based on the principle of interference of light are known as_______
interferometers
__________ are high sensitive precision metrology instruments. Accuracy & precision to scale of mm and nm
interferometers
It has been used for a long time in the
astronomical telescopes, optics industry,
and recently in biological imaging.
Interferometers
Interferometers are used to determine…
• Optical testing like surface _____,______,____
• Wavelength of ______
• Thickness of ____ strips
roughness, flatness, curvature, etc.,
light
thin
Interferometers are used to determine…
• Optical aberrations of:
- _____ displacements
- Refractive index changes
- spectroscopy
of lenses, glasses etc.
small
Shearing Interferometers can be used to determine if a coherent beam of light is \_\_\_\_\_\_\_\_
collimated.
__________shows the design and manufacturing defects before thousands of lenses are made
Surface profile
Optical coherence tomography (OCT) Corneal and Retinal Imaging
is An imaging technology based on :
Michelson Interferometry
is a noninvasive, interferometric imaging modality that provides significantly higher
sensitivity and axial resolution
than the conventional imaging systems
Optical
coherence
tomography
______is useful in finding abnormalities in the retinal
layers non invasively, which the fundus camera may not
have the potential and resolution to detect.
Optical coherence tomography
OCT
\_\_\_\_\_\_Interferometer :light from the two telescopes are brought together in an image plane to interfere, just like Young’s two-slit experiment.
Michelson Interferometer
\_\_\_\_\_\_\_\_\_\_\_\_\_ allow astronomers to reconstruct a detailed picture of the inner disc of matter around a young star.
Michelson Interferometer
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
LIGO: Laser Interferometer Gravitational wave Observatory
