Interference Flashcards
What makes a wave corgerent
Only emits one frequency and has a constant phase difference
When does destructive interference occur
When two coherent waves have a phase difference of TT
What does opd depend on
The refractive index that the medium is traveling through
When does opd occur
When two waves from the same coherent source take different routes to the detector
What is opd and gpd measured in
M
When reflected from a low to high medium what will be the phase chnage
TT radians
What is the phase change when light is reflected from a high to low reflective index
No phase change
A phase change of TT
Wavelength / 2
What happens when light hits a transparent medium
Some of the light is reflected and some of it is transmitted through in the museum (refracted)
When does thr interfenxe of waves by division of amplitude occur
When a wave is split into two comments by relefcfion and refraction before revombined later.
When does the thin flim interference occur
When light reflects from the top and bottom surfaces of a thin flim of a substance
How do the two rays revombine
Through superposition
Explain how to get to the formula opd= 2nflim d + wave/2
The 2 d from come the wave going inti the medium and coming back out so traveling twice
The ray 1 under goes a pjse xhnave of TT
Why is the cover all effect multi coloured with sunlight falls on a oil flim
Because the surface isn’t at the same thickness so some wavelengths interfere constructivly and some destructive because of the different thickness
What is bloomed coating
It is where a transparent material is deposited on a glass lens
Why is bloomed coating used
So that rhe lens will be non-reflective to certain wavelengths
What is the formula for opd for bloomed coating
Opd=2ncoating d
What is opd equal to when we need destructive interference to occur
Wavelength/ 2
How can interference fringes be produced
By a think wedge of air
What happens when the wedge is illuminated with a monochromatic source
Brigbt and dark bands are seen in thr reflected beams
What is the symbol for fringe separation
Delta x
What direction does a point spruce radiate to when light is emitted
All direction
With a monochromatic light spruce what do the point of the wave front represent
The wavefronts are coherent as they have the same wavelength and are in phase
What happens if you take two parts of a wave and combine them
Then we will see interference by divion ot wavelength
What is divion by wavelength
Occurs when two coherent waves orginiating from the same wavefront undergo interference
Where does the brighst fringe occurs on the young slits experiment
Occurs at the centre of the interference pattern as this point is equal distant from the slits and so the wave arrive exactly in phase
Where does the first dark fringe occur
On either side of this when the optical path difference between the wave is exactly half a wavelength.
What is the central bright fringe corresponds to m
M=0
D in young slits experiment
Distance between the grating and screen
d in young slits experiment
Distance between S1 and S2
For a light of a constant wavelength. As d decreased what happens to the delta x
It will increase
If D increases what happens to delta X
Increases
If D increases what happens to delta X
Increases
For a constant slit separation. If the wavelengths increased the fringe separation
Increases
For a constant slit separation. If the slit separation greater for red or blue light
Greater for red
Which colour diffraction the most red or voloit
Red
Which colour diffraction the most red or voloit
Red
Colour order
Vilet, indigo, blue, green, yellow, orange, red
