State and explain why the core is made as narrow as possible:
Application of optical fibres and explain how it has benefited society:
Differences in patterns obtained from laser compared to a white light source:
How does the wave theory of light account for areas on screen where intensity is a minimum?
How can a guitarist raise the fundamental freq of a vibration of a string?
Total internal reflection occurs only when:
Reduced amplitude of a pulse travelling along an optical fibre due to:
Why do optical fibres have cladding?
Pulse broadening along an optical fibre due to:
There has to be a phase difference of a multiple of wavelength in order for the waves to be in what?
Describe how the diffraction pattern would change if light with longer wavelength was used:
How would fringes appearance change if slit was made narrower?
Refractive index=
What is the equation for the refractive index when the light travels into a denser medium?
What is the name for when light passing through each slit spreads out?
Blue wavelength and frequency compared to red is:
Explain the formation of fringes seen on the screen from a double slit experiment:
- prevent signal loss (from core to fibre)
- -which would cause data to be weaker/to make better quality signal
- avoid multipath dispersion
- -which would cause poor resolution
- increase probability of total internal reflection (TIR)
Application of optical fibres and explain how it has benefited society:
- endoscope
- -improve medical diagnosis
- communications
- -high speed internet
Differences in patterns obtained from laser compared to a white light source:
- laser= monochromatic
- laser= more intense
- laser= dots compared to fringes
How does the wave theory of light account for areas on screen where intensity is a minimum?
- destructive interference
- (light form one slit meets light from the other) in antiphase (180* out of phase)
How can a guitarist raise the fundamental freq of a vibration of a string?
- tighten string
- make string length shoter
- increase tension
Total internal reflection occurs only when:
- light travels from a higher refractive index to a lower refractive index
Reduced amplitude of a pulse travelling along an optical fibre due to:
- energy loss (within fibres)
Why do optical fibres have cladding?
- prevent scratching of the core
- keeps signals secure
- strength for fibre/prevent breakage (given core needs to be thin)
- maintains quality.reduce pulse broadening
- prevent crossover of data/signal from other fibres
Pulse broadening along an optical fibre due to:
- multipath dispersion
There has to be a phase difference of a multiple of wavelength in order for the waves to be in what?
- in phase
Describe how the diffraction pattern would change if light with longer wavelength was used:
- maxima further apart
- central maxima wider
How would fringes appearance change if slit was made narrower?
- lower intensity
- increased separation
Refractive index=
- indication of how many times slower light travels
What is the equation for the refractive index when the light travels into a denser medium?
- n=sin(i)/sin(r)
What is the name for when light passing through each slit spreads out?
- diffraction
Blue wavelength and frequency compared to red is:
- smaller
Explain the formation of fringes seen on the screen from a double slit experiment:
- interference
- where light from 2 slits overlaps/superposes
- bright fringes formed where light reinforces/constructively interfere
- dark fringes are formed where light cancels/destructively interfere
- the light is coherent
- cancellation occurs where light waves are out of phase of 180*