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Flashcards in Thin Film Interference Deck (15):
1

If a patient has a cataract, can you assess visual performance of his/her neural system to determine if surgery is justified?

-two coherent points sources placed in a clear part ofhte pupil can be used to stimulate the reinstated with an interference pattern, thus bypassing the the optics to assess the neural system.
-a 100% contrast fringe forms at the retina. This clever technique permits the clinician to test the neural system of the patietns eye without contamination by the cataract

2

Thin film interference is a ________ by amplitude

Division by amplitude

3

Thin film interference is due to _______ processes. This is the _________

-multiple reflection
-wave effect

4

For a thin film, what is long enough to cause interference effects?

Coherence length of ordinary light is long enough

5

Thin film interference is based on two conditions

1. Path difference
2. Phase change

6

Phase reversal

-Gets inverted with fixed ends
-does not get inverted with a free end

7

When does 180 degree phase change happen?

When light traveling in lower RI medium reflects off higher RI medium

8

Principle of optical reversibility

In the absence of any absorption, a light ray that is reflected or refracted will retrace its original path if its direction is reversed

9

Whatever happens on ________, the opposite happens on ________

-reflection
-transmission

10

Phase change when going from denser to lighter medium

None

11

Phase change when going from lighter to denser medium

180 degree phase change

12

Reflected rays in thin film

2t=mlambda/n
Destructive interference
Minimum reflection

13

Transmitted rays in thin film

2t=mlambda/n
Constructive interference
Maximum transmission

14

Important factors to consider before resolving thin film interference problem

-path difference
-phase change
-materials on both sides of the thin film

15

No _______ on transmission

Phase change