Read about interference | 106 Discussions | Page 1

  1. F

    I Why find the highest order maxima/minima in slit equations?

    I have been seeing interference and diffraction problems involving the double slit and single slit equations that ask for things like the "highest order maxima" or minima, which I have learned are basically found by setting the angle to 90 degrees. My question is are there any real world...
  2. guest948

    Interference pattern (easy?)

    I guess C: constructive interference pattern along the central line. Am I correct?
  3. K

    B How do orthogonal waves interfere?

    How do two highly directional, orthogonal light beams (or any other kind of waves) with the same frequency interfere with each other?
  4. M

    Formula for calculating wavelength of sound waves in interference?

    The values calculated was nowhere near the theoretical values, though I guessed they won't be as the results recorded was incredibly inaccurate. My teacher acknowledged the fact the final values won't be close to the theoretical ones but also said that my formula was wrong, that it works to find...
  5. L

    I How can a single slit diffraction create an interference pattern?

    I explained that Huygens principle states that each point on the wave front act as a point source which produces spherical waves which produce the interference pattern. Now his question is that where are these points and wouldn't there be infinite number of points on each wave front creating...
  6. K

    Measuring the Distance between the Fringes of a Diffraction Grating

    I have been preparing for a physics practical on diffraction. More specifically, we will use a CD as a transmission grating (by peeling off the reflective layer), and measure the distance between the fringes for a specific distance between the CD and the viewing wall. However, it is unclear...
  7. K

    Diffraction Grating: Possible variables for Experiment

    For my High School Physics course, I have been tasked to design an experiment investigating the properties of a CD diffraction grating, and we MUST make a graph. Unfortunately, we only have two lasers of different wavelength, so changing the wavelength and measuring ##theta## would be a bad...
  8. Kharrid

    Two Speaker Destructive Interference

    I already have the solution in front of me, I am wondering why there is a difference in the formula for path difference. I've attached the problem as well to show the Figure. What I am struggling to grasp is why the path difference for the angles closer to A is dsin(Θ) = (m+1/4)λ while the path...
  9. F

    B Question about wave interference and coherence

    I have encountered the following definition of interference: Interference is a wave phenomenon in which two or more waves from coherent sources meet and superpose to form a resultant wave such that the amplitude of the resultant wave at any point is the vector sum of the amplitudes of the...
  10. S

    I Mach-Zender-Interferometer with polarizers

    I have a question on how exactly polarizing filters would influence interference in a Mach-Zehnder interferometer. To explain, I'll show some configurations and what I would expect to happen - please tell me if I am incorrect anywhere. Here is the standard MZI configuration with no filters and...
  11. christang_1023

    I Derivation about the wave interference

    Starting from the simple case, there is a single wave ##e=a\cos(2\pi ft+\frac{2\pi}{\lambda}x+\phi_0)##, and integrate in such a way, where ##T_{eye}## stands for the response time of human eyes' response time towards energy change: $$I=\int_{0}^{T_{eye}}e^2dt$$ The calculation includes...
  12. Baibhab Bose

    Fringe spacing of the Interference pattern due to two Coherent waves

    Homework Statement: In the attached image. Homework Equations: formulas of fringe width and phase differences I think. It has been a long time since I have dealt with these kinds of interference/fringewidth problem, I cant figure out a way to start solving this problem. I was thinking about...
  13. S

    B Phase shift in Mach-Zehnder interferometer

    I'm confused by the phase shifts in a Mach-Zehnder interferometer because I keep finding two different explanations. One explanation (for example, given on Wikipedia, but also elsewhere) states that on each reflection, the phase shift is 180 degrees, but only, if light is reflected from the...
  14. A

    I What do these submaxima represent - Interference Pattern

    Hey all, Here's a neat picture: The green arrow points towards one of the submaxima that I am curious about. It's the submaximum of the curve labeled 1. 1. represents the interference pattern 3. represents the diffraction pattern 2. represents the irradiance pattern I guess that those...
  15. F

    The maximum intensity for light transmitted through a thin film

    Homework Statement A thin (460 nm) film of kerosene (n=1,20) is spread out on water (n = 1,30). Light hits the (horizontal) surface of the film coming (almost) perpendicularly from above. A diver underwater, below the film. a) Find out the visible wavelength reflected into air that has the...
  16. E

    B Interference from a thin film

    Hello, I have a question about interference. I have interference from thin film, i.e. fringes of equal inclination. How I can calculate the radius of sample curvature from the interference pattern? How I can to determine the maximum radius of curvature of the surface at which interference will...
  17. A

    I Coherence, Young's double slit experiments.

    In most textbook/internet explanation of light coherence, it gives two conditions 1) monochromatic light, same frequency. 2) light in phase or constant phase difference. Only with the two conditions can light interference pattern be observed in the double slit experiment. But this cannot be...
  18. Cc518

    Interference of sound waves

    Homework Statement Two in-phase loudspeakers, which emit sound in all directions, are sitting side by side. One of them is moved sideways by 3.0 m, then forward by 4.0 m. Afterward, constructive interference is observed 1/4 and 3/4 of the distance between the speakers along the line that joins...
  19. Penguin98

    Interference question

    Mentor note: Thread moved from Adv. Physics Homework 1. Homework Statement Light is incident normally from air onto a liquid film that is on a glass plate. The liquid film is 174 nm thick, and the liquid has index of refraction 1.60. The glass has index of refraction n = 1.50. Calculate the...
  20. P

    The Difference Between Diffraction And Interference Patterns

    I've recently come across this problem: Answer true or false. If light shines through 2 slits, will the diffraction pattern always be within the interference pattern. I don't understand this question, however. How can the interference and diffraction pattern be separated in this situation...
  21. MatthijsRog

    B What constitutes a closed end in acoustic resonance in tubes

    Dear all, For my students, I'm currently trying out some experiments they can do to simulate acoustic processes. One of the topics that we will be discussing is that of standing waves. Although I have never done it before--I come from a completely different background--I want to create...
  22. ccdani

    A Transmission of blue light through ceramics and surface roughness effects

    Hey :) I measured the transmission of blue visible light (350-550nm) through lithiumdisilicate ceramics with an ulbricht ball and an spectrometer. The light source was a led dental curing unit (bluephase style). The light guide was positioned direct on the ceramics. Now I wanted to test...
  23. Jeremy Feng

    Young's Modulus Experiment With a Glass Screen

    Homework Statement Homework Equations Path difference is nλ at maxima, (n+0.5)λ at minima The Attempt at a Solution I think the phase difference between S1 and S2 is not 0 anymore, because the wave effectively takes a longer distance by going through S2. Thus, there is no longer a central...
  24. T

    I Destructive interference for distance-specific illumination?

    From a practical standpoint, can we combine two (or more) lasers tuned to almost-but-not-quite identical frequencies to create distance-specific illumination? For instance, say we have a 1 micron laser and a 0.9999 micron laser which we combine through some beam-combiner optics. In theory I...
  25. F

    Double slits and convex lens interference

    Homework Statement Two slits (of width ##a=39 \mu m##) are lighted up with a monocromatic wave of ##\lambda=632,8 nm##. The distance between slits and the screen id ##D=4 m##. The distance between the slits id ##d=195 \mu m##. In front of the slits there are a convergent lens with focal lenght...
  26. malak

    I Michelson interferometer dimensions

    hi i want to design michelson interferometer device for measuring small distance movement i am using laser diode with a wavelength 635 nm and power 3 mw can any one tell me how can i decide the dimensions (from source to beam splitter , for beam splitter to fixed mirror , from beam splitter to...
  27. C

    I Analysis of Ultrasonic Waves at a point

    I have a question regarding a theoretical analysis of Ultrasonic waves : The next picture represents a system of transducers sitting on fixed boards: Datum: * there are 4 transducers ( represented by blue color , indexed by letter ' T ' ) , each outputting Ultrasonic wave (represented by...
  28. R

    B Sound wave interference

    I collected this data by moving a sound level meter slowly through a total lenght of 0,75 meter between two speakers pointing towards each other. The wavelength of the sine waves was 0,343 meters and the frequency was 1000 Hz. The sound level meter measured the sound in dbA 20 times a second...
  29. M

    Inteference Fringes of Double Slit Experiment in Water

    Homework Statement Suppose a double-slit experiment is immersed in water (with an index of refraction of 1.33). When in the water, what happens to the interference fringes? Homework Equations λ = λ0 / n y = (λmL) / d d = distance between slits L = distance to viewing screen n = index of...
  30. S

    Double Slit Wave Interference - what is m?

    Hi, I'm doing a very simple problem, but I don't understand the diagram provided (see image below). What is m here? I know that m is the order with respect to the central bright fringe, but there isn't a central bright fringe (assuming those circles are the bright fringes)? Homework...
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