Interference Definition and 999 Threads

  1. S

    Formula for maximum interference for reflected light (thin - film)

    The light comes from glass to boundary of glass and soap film, then there will be light which is reflected and transmitted. The reflected light has no phase shift and the transmitted light will hit the boundary of soap film and vacuum and the reflected light from this boundary will also has no...
  2. J

    Electronics How do sensors handle interference due to the reflected ray?

    I am unable to see how a sensor where the receiving and emitting instruments are next to one another deal with wave interference between the emitted and reflected wave.
  3. AN630078

    Sound Wave Interference and Finding the Path Differences with Diagrams

    Question 1: a. λ=v/f λ= 340/85 λ=4 m b. Please see attached. Ihave tried to accurately and to scale construct a diagram representing the compressions and rarefactions of the sound waves. Since the wavelength of a wave is simply the length of one complete wave cycle, and I have found that the...
  4. LCSphysicist

    Easy interference problem regarding Newton's rings

    Unfortunately, i found r² = (R1)(R2)(λ)*(n-1/2)/(R1-R2) I imagined a difference of phase λ/2 on the blue ray. The grey is the air maybe polluted, as currently
  5. Mayan Fung

    Controlling output light power by constructive/destructive interference

    In optical communications, one of the modulation methods is to control the optical power (Simplest case, for example, bright = bit 1, dim = bit 0). I learned that we can achieve this by a Mach-Zehnder modulator (MZ modulator). Simply speaking, the principle of MZ modulator is to split the input...
  6. ItsKurious

    Interference of light by splitting the wavefront and recombining

    In the above diagram, I have illustrated what is written in the summery. So, if the thickness and refractive index of the material are chosen such that the part of the wave that travels through the slab acquires a path difference of λ/2 and at the right end if I keen another convex lens so as to...
  7. David Charles

    I Double Slit Interference Question II

    A stream of photons pass through a double-slit. The photon stream emerging from each slit then passes through a crystal which splits each photon into coherent entangled pairs. One photon from each pair heads towards a detector (D0) that "can be scanned by a step motor along its x-axis for the...
  8. David Charles

    I Double Slit Interference Question

    A laser provides a constant stream of photons which pass through a double-slit. The photon stream emerging from each slit then passes through a crystal which splits each photon into coherent entangled pairs. One photon from each pair heads towards a photosensitive screen and the entangled twin...
  9. S

    Constructive, destructive interference help please

    hi, i understand how to get to this equation, and this is the equation that gives the answer. However, the question asks for dark fringes which is destructive interference? would you not use m/2? so instead of the denominator (2*t) would it not be (4*t)? thanks in advance!
  10. S

    Interference pattern for two glass plates closely separated and tilted

    hi, i know you have to use 2t/lambda= m/2 to get the answer of 10.9 um. However i was taught that there would be phase difference caused by reflection, since n1(air)< n2(glass). SO the equation in my head would be 2t/lambda - 1/2= m/2. Can someone explain why I'm wrong?
  11. Erik Ayer

    I Interference of a fat laser beam: Tilting wave peaks

    I want to split a fat laser beam and interfere it with itself, kind of like this: The very obvious problem is that the wave peaks shown as black lines would be a whole lot closer together, so the interference fringes would be sub-microscopic. If a couple of glass wedges - oddly-shaped prisms...
  12. R

    Interference: Factors that reduce the widths of primary maxima

    The ranked order from most to least effectively reducing the widths of the primary maxima is: A>D=C>B. I know that doubling the wavelength of incident light will double the width (y) of the fringe. This means that doubling the frequency of incident light will reduce the fringe width (y) by half...
  13. Y

    Diffraction, interference, single and double slit setups

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  14. garthenar

    Intensity and Interference Patterns (double slit)

    I'm still on part a. I think that i may have the wrong equation for intensity. I'm not sure I'm using the right numbers for the "first minimum". I started with getting the wavelength λ=(ax)/D since the first minimum occurs at m = 0.5 I multiplied the distance to the first minimum by 2 to get...
  15. J

    Will closing the slit affect the clarity of observing light interference?

    My guesses are that if slit is almost closed, then the width is comparable to the wavelength and diffraction will occur. does this means that he will observe the slit S clearly or less clearly? [Picture cleaned up a bit by a Mentor]
  16. H

    Destructive interference near two speakers

    where x is the distance from one speaker 343=(66)(5.197) wave length =5.197m x-(50-x)=(5.197)(m+0.5) I choose m=-10 2x-50=(5.197)(-9.5) x=0.314m? Prof says correct answer is 1.6m tho
  17. 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?
  18. ChrisXenon

    Photographing diffraction grating interference patterns

    If I direct a laser pointer onto a diffraction grating and place a screen beyond it, I see a diffraction pattern - a line of dots - as expected. If I move the screen further away from the grating, the distance between the dots increases - again as expected. If I place a camera where the screen...
  19. H

    Formula for calculating the wavelength of sound in interference

    Here is a diagram of experiment: Here is the results: Average distance between nodes (cm) Frequency (hz) Line 1 Line 2 Line 3 500 253 176 105 1000 333 438 None My analysis: ƛ/2=D ∴ƛ=2D where ƛ=wavelength (cm) D=distance between nodes/antinodes (the average,cm) 500hz: Line 1...
  20. 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...
  21. U

    Methods for capturing a Fabry-Perot Interference Pattern

    I'm planning on doing an (undergraduate-level) experiment to study Zeeman Splitting in Cadmium. There's no complete set of instructions for the lab, but after seeing the materials, it appears that I will attempt to use a cylindrical Fabry-Perot Etalon to resolve the wavelength differences...
  22. S

    Optics: Destructive Interference

    I thought if the question asks for the first minimum or the first dark fringe you use (m+1/2) but i am not getting the right answer. I was hoping if someone could tell me in what situations the (m+1/2) would apply? Thanks in advance.
  23. L

    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...
  24. 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...
  25. 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...
  26. K

    I Photon interference and path differences

    Most sources I come across on the topic of photon interference focus on the phase differences, but neglect discussion on the wave amplitude. Wave amplitude diminishes with distance; a single photon's energy does not. So in a double slit experiment with photons being emitted one at a time, if...
  27. E

    Strategy for interference problems

    For instance, consider two sources of light ##S_{1}## and ##S_{2}## where ##S_{1}## is emitting with a phase angle ##\frac{\pi}{4}## greater than ##S_{2}##. The light from ##S_{1}## travels a straight distance ##d_{1}## through a medium of refractive index ##n_{1}##. The light from ##S_{2}##...
  28. A

    What Causes the Angle-Insensitive Colors in Bird Feathers and Butterfly Wings?

    I have long been puzzled by the colors of bird feathers and butterflies. They are mostly attributed to interference in microscopic structures, not dyes, yet do not display the typical change of color with viewing angle of interference colors. Why? There are a few exceptions; some butterfly spots...
  29. 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...
  30. B

    Interference Intensity: Questions & Answers

    Hello! I am a bit confused by the formula for light intensity in the case of interference. In the books and online resources that I read, this is given as: $$I = I_0 \cos^2(\frac{\pi d \sin \theta}{\lambda})$$ where ##d## is the distance between the slits, ##\lambda## is the wavelength of the...
  31. F

    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...
  32. B

    Two-point source interference pattern

    I'm having trouble understanding what it's asking me. "Calculate the angles at which the nodal lines in the pattern are located far from the sources." I assume they are very far away, making lines PnS1 and PnC parallel. Is the question asking me to calculate θ' in the example? "nodal lines"...
  33. I

    Is the Fabry-Perot Interference Dependent on Pulse Duration?

    I get that a single (optical) pulse is a superposition of continuous frequency components of its spectrum, but I'm a bit confused how Fabry-Perot interference can be interpreted in time domain. In a single-frequency explanation, the idea is that the incident wave goes through multiple...
  34. Addez123

    Find Wavelength of Light Wave for Optimal Constructive Interference

    The green ray is moved upwards for clarity, they are all on same x-axis with no y component. Theres a phaseshift at both reflections of the green light because n1 and n3 are > n2. This results in a complete wavelength phaseshift, aka no impact on the wave. That means that only the extra travel...
  35. dazaireta

    Linear Polarization Interference: Can It Happen?

    Two waves are linearly polarized. The electric field of one wave is aligned with the x-axis and the other is aligned with the y-axis. In the absence of matter that might change the polarization, can these waves interfere with each other?
  36. Erik Ayer

    I Complementarity Of One- And Two-Particle Interference

    It seems to be quite difficult to find information on this phenomena, although there are a couple cases of people asking about it. From what I understand, if downconverted light is sent through something to create interference such as a double-slit or Mach-Zehnder interferometer, there will be...
  37. 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...
  38. D

    Audio interference of sound waves from two speakers

    Homework Statement: Two identical audio speakers, connected to the same amplifier, produce monochromatic sound waves with a frequency that can be varied between 300 and 600 Hz. The speed of the sound is 340 m/s. You find that, where you are standing, you hear minimum intensity sound a) Explain...
  39. christang_1023

    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...
  40. 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 can't figure out a way to start solving this problem. I was thinking about...
  41. S

    Radiation interference with camera at Chernobyl?

    Hi all, My first post on this forum. I couldn’t think of anywhere better to come than to here with a question I’ve had since a recent trip to Chernobyl! Whilst visiting Pripyat I took several videos. Great care was taken to stay away from any contamination hot spots and we had an experienced...
  42. zeronem

    I Photon states and interference in an Interferometer

    Hello. I have a question. In the book I am reading, They derive the Ubs operator applied on a photon state with the beam splitter at a ratio of 50/50. A beam splitter that is used in the Mach-Zehnder interferometer. I'm having a hard time deciphering whether the formula for beam splitter...
  43. VVS2000

    Interference Pattern from two coherent light sources

    Can anybody explain why the bright and dark fringes exist during the the interference phenomenon from two coherent sources.. I wanted to know why that specific pattern occurs
  44. RealKiller69

    Diffraction -- Calculate the interference lost orders due to diffraction

    I have calculated the diffraction part for each one of the slits but I am not getting any lost order.
  45. C

    How to know what m value to plug into thin film interference equations

    How do I work out what m value (0, 1/2, 1 etc) to put in the thin film interference equations like 2nt = (m + 1/2)*lambda? Does it depend if it's constructive or destructive? Could someone help explain, thanks!
  46. 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...
  47. M

    B Double Slit Wave Interference With Single Electrons

    I have heard that wavelike interference patterns are observed in the double slit experiment even when electrons are fired one by one. https://physicsworld.com/a/the-double-slit-experiment/ My knowledge on the experimental setup is very basic. The reason I am posting here is out of curiosity...
  48. S

    Number of interference fringes based on n open slits

    Hi, Is there an equation that gives you the number of interference fringes if you know the light wave length, size and separation of the slits, and length from the slits to the screen?
  49. A

    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...
  50. .Scott

    I Is there a term for this type of unknown experimental interference?

    You collect 200 data points, 100 with input ##A## and 100 with input ##A'##. For all 100 ##A## you get output ##C## and for all 100 ##A'## you get ##C'##. That's way more than 5 standard deviations, so you're ready to publish... But not really. Because what matters is not just that input ##A##...
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