- #1
Ahsan Khan
- 270
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Hi all
To observe interference of light waves in Young's Double Slit Experiment one needs to have coherent sources.Some,doubts are coming in my mind regarding coherent sources.
Q1. Will it make sense to talk about a single source as coherent source(not sources)
Also two(or more) sources are said to be coherent if they have same frequency and a constant phase difference.
Q2. Can we call the two sources as coherent if the frequency of both sources keep on changing such that at any time the two sources have the same frequency so that their phase relationship do not affects?
In my text they say if we use two sodium lamps for interference no interference fringes will be observed because the light wave from an ordinary source like a sodium lamp undergoes abrupt phase changes in time of the order of 10^-10 seconds.
Q3. Is it mean that two separate sources couldn't act as coherent because of each source produce wave(light) discontinuously and that at the point of emission their phase varies with time; that is each of the sources undergo *ABRUPT* phase changes with time? Or(and) do the two separate sources don't make up coherent set because(as the correct or another reason) that their frequencies do not match?
Q4. I mean the what I must assume, what is the core problem of creating coherent condition from two independent separate sources?
Q5. Lastly Young made use of sodium light it is said that he produces coherent sources by dividing the the same wavefront through double slit, in his case would the frequencies(both of which are same) were fixed with time(in case of sodium light he used) or it was just their phase differences were remain constant? If the frequency do no change it means sodium light is able,to produce monochromatic light if frequency(and hence wavelength) was changing(keeping phase relationship of two slit as source same) then how did he observe the position of maxima or minima(dark and bright) pattern of interference).
Thanks a bunch
Regards
To observe interference of light waves in Young's Double Slit Experiment one needs to have coherent sources.Some,doubts are coming in my mind regarding coherent sources.
Q1. Will it make sense to talk about a single source as coherent source(not sources)
Also two(or more) sources are said to be coherent if they have same frequency and a constant phase difference.
Q2. Can we call the two sources as coherent if the frequency of both sources keep on changing such that at any time the two sources have the same frequency so that their phase relationship do not affects?
In my text they say if we use two sodium lamps for interference no interference fringes will be observed because the light wave from an ordinary source like a sodium lamp undergoes abrupt phase changes in time of the order of 10^-10 seconds.
Q3. Is it mean that two separate sources couldn't act as coherent because of each source produce wave(light) discontinuously and that at the point of emission their phase varies with time; that is each of the sources undergo *ABRUPT* phase changes with time? Or(and) do the two separate sources don't make up coherent set because(as the correct or another reason) that their frequencies do not match?
Q4. I mean the what I must assume, what is the core problem of creating coherent condition from two independent separate sources?
Q5. Lastly Young made use of sodium light it is said that he produces coherent sources by dividing the the same wavefront through double slit, in his case would the frequencies(both of which are same) were fixed with time(in case of sodium light he used) or it was just their phase differences were remain constant? If the frequency do no change it means sodium light is able,to produce monochromatic light if frequency(and hence wavelength) was changing(keeping phase relationship of two slit as source same) then how did he observe the position of maxima or minima(dark and bright) pattern of interference).
Thanks a bunch
Regards
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