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Questions tagged [interferometry]

Interferometry is the name for a class of measurement techniques based on the interference of coherent optical fields or other electromagnetic radiation. Generally, Interferometric measurements are extremely accurate, but can be difficult to perform. Common uses for interferometry are optical component metrology and stellar interferometry, although there are many applications.

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Modifying the Michelson interferometer [closed]

If additional beams splitters were to be introduced to one of the beam paths in a Michelson interferometer leading to production of additional beams, each assigned a detector. Like this; Circles ...
Precious Adegbite's user avatar
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Confused about the principle Of Michelson Interferometer

Consider the figure that I found from an answer here: Michelson interferometer circular fringes Now the path difference in the image in clearly $$\Delta d= 2d cos\theta$$ and I know a phase ...
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Interferometer designed to create diffraction in free space

I designed the following interferometer: If the light beam -theoretically- is very narrow , will light be diffracted away from point B from QED's perspective?
Wael Khatib's user avatar
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3 answers
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Mach-Zehnder interferometer and superposition

I've a doubt on interpretation of superposition in the interferometer Is it correct to say that in the Mach-Zehnder interferometer, the photon exists in a state of quantum superposition of the two ...
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Understanding the math of the Michelson-Morley experiment

I'm having some conceptual misunderstandings of the Michelson-Morley experiment. The time for the beam going perpendicular ($t_{across}$) of the aether wind I am getting: $$(ct)^{2}=d^{2}+(vt)^{2}\\ (...
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Double slit with off centre source, where does phase difference occur?

I am currently working through the following problem for my optics class. The setup as shown below is composed of a double slit sandwiched between two convergent lenses L1 and L2. A point source is ...
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Which method of laser diode operation is less likely to cause mode hopping: constant current or constant power?

If a laser diode is uncolled and operates in a CW mode then which method of operation is less likely to cause mode hopping: constant current or constant power?
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Does QM recognise empty waves?

If a particle (photon) goes through a Mach-Zehnder interferometer it is accepted in quantum mechanics texts that in passes in both channels after first beam splitter BS1 and propagates there until BS2....
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Why are the Michelson-Morley experimental results interpreted more broadly than the scope of the tested medium?

My understanding of the experimental design is that they tested for a stationary, luminiferous, light propagating, non-interacting with mass, uniform, ubiquitous medium. This is but one possible ...
GravityTim's user avatar
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Why fiber optic Sagnac interferometers don't produce multiple interference fringes

I have seen a few Sagnac fiber optic interferometers however, those that I've seen don't produce multiple fringes but rather just one luminant dot with varying intensity. Even if a beam expander is ...
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How to align a Mach-Zehnder at 810 nm?

I have a task to arrange MZI using very weak source with photons coming one at a time. On top the wavelength is 810 nm. How to 'see' the interference pattern to 100% in one channel and 0% in other. I ...
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What are the disadvantages of using a single mode Fabry-Perot laser diodes in interferometry, as opposed to distributed feedback laser diodes?

What are the disadvantages of using a single mode Fabry-Perot laser diodes in interferometry, as opposed to distributed feedback laser diodes? I'm specifically interested in potential problems that FB ...
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Mach Zehnder Do-it-yourself

I have a red laser and BS. Can I make MZI at the lab? I heard that is very difficult to achieve the calibration. What is expected to be seen after BS2? A dark spot at centre with fringes around? I ...
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Is the interference stable?

In a Mach Zehnder interferometer if we use one at a time photons and tune it so the first several to arrive in channel D1 after BS2 will all next arrive also in D1? Are there reasons that some will ...
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Phase difference in Michelson Interferometer

I'm currently taking a quantum mechanics course in university and our professor introduced us to the Michelson Interferometer (or at least what I believe is an apparatus based on it), where a light ...
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Mode Interferometers (MMI) versus waveguide couplers

In Photonics Integrated Circuits Mach-Zender (MZ) modulators are very often used. This design splits one wageguide into two spatially separated waveguides and makes them to rejoin, in order to ...
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How HBT interferometery works?

I am still confused about how HBT interferometry for star angular size works after reading about it on the internet and in papers. Mathematics usually does not help before I do not catch the way the ...
saldenisov's user avatar
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What are the similarities between a beam splitter and a double-slit?

More generally, my question is about the similarity between an $N$-slit and an $N$-mode beam splitter. Conceptually speaking, would it be accurate to say that the beam splitter is just the discretized ...
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Can LISA observe BH beyond the observable universe?

Reading the paper "Astro2020 Science White Paper Where are the Intermediate Mass Black Holes?", and the plot in Fig.1, page 5, it seems LISA can see IMBH beyond 100 Gpc...Since the ...
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How close to reality is my handwaving argument about Fabry Perot interferometers?

Under this answer to https://astronomy.stackexchange.com/q/55437/7982 I wrote a comment where propose the uncertainty inequality roughly written1 as $\Delta E \Delta t \ge h$ or for photons $\Delta \...
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Which experimental setup replicating Michelson-Morley experiment had the longest path of light?

After the Michelson-Morley (MM) experiment many scientists performed similar experiments using the original MM experimental setup, or different derivative experimental setups employing lasers and ...
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Is it possible to create Fabry-Pérot Interferometer with one partially transparrent and one non-transparent mirror?

In the literature sources I've found so far about Fabry-Pérot interferometer there are only example schematics of the interferometers in transmission - light source is placed from one side of the ...
Andrii St's user avatar
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Michelson interferometer moving mirror by half wavelength

With expanding beam I understand I will get circular fringes, and I understand if you move the mirror by d the path difference change of the interfering beam is $2dcos\theta$. But I don't understand ...
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Single-photon interferometry with fibers: the very first experiment

I am looking for the very first published experiment in a relevant journal with all the following features: Michelson or Mach-Zender light interferometry is demonstrated The arms of the ...
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Getting the power spectrum from an interferogram

I'm doing analysis for a laboratory task where we used a stepper motor to vary the position of a mirror (in a Michelson interferometer) to get interferograms using different light sources. I have been ...
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Question on Feynman's Improved Stern-Gerlach Experiment rotated about the $z$-axis

I'm having trouble understand Feynman's reasoning that particles in Fig. 6-5 (b) will end in an unknown state. Feynman reasons quote: Suppose that we put an apparatus in front of S which produces a ...
trying2understand's user avatar
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1 answer
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Atom Interferometer Contrast

I have made a simulation of a Raman beam based atom interferometer in a Mach-Zehnder configuration. In this way, the electronic state of the atom changes as well as the momentum when diffraction by ...
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What is the allowed wavelength range over which the Fabry Perot intensity pattern is formed?

I'm working with a Fabry Perot cavity with a length of 55 mm and an incident wavelength of 1550 nm. From theory the FSR of the FP cavity can be either computed using the equation FSR = λ^2 / (2 n L) ...
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What are the causes for $g2$ ( intensity) value changes in a Mach-Zehnder setup at a fixed reference path and fixed sample?

I'm using a Multimode laser passing it through a Mach-Zehnder interferometer. I am able to get almost constant $g2$ (intensity) from the sample. However, the reference arm intensity keeps fluctuating ...
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How exactly does Ligo achieve complete destructive interference with just an interferometer?

Ligo works by destructively interfering light from a laser using an interferometer. Its said that no light enters the photo detector when all mirrors are the same distance. However,based on my ...
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Decomposing circular diffraction patterns

I have the following diffraction pattern produced by a fabry-perot etalon The red represents the center of that pattern. Taking the mean intensity of the pattern as a function of the radius from the ...
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Pattern of source-tracking two-element radio interferometer

In a two-element adding Interferometer, the phase difference comes about as EM-waves from a source at an angle $\theta$ to the baseline-normal generally cover different path lengths when travelling to ...
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Michelson interferometer: beam splitter affects amplituedes?

Let's suppose an initial plane wave $\vec{E}=\vec{E_0}e^{i(\vec{k}\cdot\vec{r}-\omega t)}$ enters a Michelson interferometer . Let $\vec{E_1}=\vec{E_{01}}e^{i(kz-\omega t)}$ and $\vec{E_2}=\vec{E_{02}}...
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Lowest numerical aperture SIM microscopy

What is the lowest numerical aperture objective that can support SIM microscopy? Also, how does the NA affect the spatial frequency or contrast of the resultant standing wave?
selene flemming's user avatar
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How is a delocalised state realised and what is its wavefunction?

Gravitationally induced entanglement experiments aim at studying the quantum nature of gravity trough the interaction of a delocalised particle state with another system. The various papers on the ...
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Fabry-Perot interference pattern at non-normal incidence

I'm confused about exactly how the interference happens. The original beam (at the bottom) comes in at an angle, and multiple reflected rays come out of the second mirror. But those rays are spatially ...
user376234's user avatar
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How does the change in cavity length effect the interferometric frequency of a Fabry Perot cavity?

I'm working with FBG-based Fabry Perot interferometers, considering three FBGs in series to create 2 FP cavities. I'm confused about the following two things and cannot seem to get clear answers from ...
Dhyana's user avatar
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2 answers
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Difference between LIGO and Michelson-Morley interferometer

The LIGO interferometer looks like a huge Michelson-Morley experiment showing interferences and the gravitational waves are described as waves propagating on the 'spacetime fabric'. LIGO detects ...
Gerard Zonus's user avatar
3 votes
1 answer
597 views

Elitzur-Vaidman Bomb Detector

The Elitzur-Vaidman bomb detector is a theoretical device that can detect whether photon-activated bombs are functional without detonating all of the test bombs by using quantum mechanics principles. ...
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Phase Shifting Beam Splitter

I am trying to make sense of all these answers in: Phase added on reflection at a beam splitter? and web search results. So my understanding is that the actual phase shift depends on the beam splitter ...
Duke William's user avatar
1 vote
2 answers
298 views

Interference in split and recombined beam

let us consider the following setup of beam splitters: single photons enter beam splitter A with R/T ratio of 50:50 and split into two paths A1 and A2. A1 undergoes a phase shift of X and then using ...
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How to model the effects of diffraction for a convex lens?

I am using a convex lens in a wavefront-measuring interferometer for testing microscope objectives, where the lens images the exit-pupil of the objective onto my camera. It is my understanding that ...
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Griffiths Consistent histories MQS state in Mach-Zehnder experiment

In Robert B. Griffiths' Consistent Quantum Theory, he describes a variant of the Mach-Zehnder interferometer experiment where a detector represented by "off" state $\lvert 1\hat{e}\rangle$ ...
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Aqueous Equivalent of the Michelson-Morley Experiment [closed]

This question relates to the Michelson-Morley experiment and whether anyone has so far proposed an equivalent experiment using aqueous waves instead of optical waves. If it is true that (i) The ...
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1 answer
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The purpose of acoustic optical modulator (AOM) in Heterodyne Interferometry for Plasmas

I do not understand the purpose of an acoustic optical modulator (AOM) in a heterodyne interferometry system. Take the system below as an example (taken from a UW Dissertation) My understanding for a ...
Erik McKee's user avatar
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Explain laser stability and interferograms relationship

I am using a Twyman-Green interferometer to record phase-stepped interferograms. The interferometer uses a monochromatic diode laser (visible light). As you observe the interferogram on the screen, ...
Hikikomori's user avatar
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0 answers
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Fringe pattern and ripples in the fringe visibility plot from interferograms

I am using a lens testing interferometer, where I record 4 to 5 interferograms with a 90$^{\circ}$ phase step between consecutive interferograms. In addition to the interferometer, I have also created ...
Hikikomori's user avatar
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1 answer
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Single-Antenna-Single-Pass SAR interferometry

As I understand, for elevation mapping using InSAR, one typically requires an out-of-plane baseline to create the required phase difference between images to detect objects at height. This usually ...
Jan Lynn's user avatar
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2 votes
2 answers
240 views

How does partially constructive and partial destructive interference work in interferometers?

From what I have gathered, complete constructive or destructive interference results in all light or no light traveling a given path of an interferometer (correct me if this is incorrect). However, ...
OneStrangeQuark's user avatar
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What Is The Easiest Way to Measure a Short Distance With Laser Light?

I'm an EE, so please forgive if this question is dumb. The word "easiest" means, "What requires the least amount of optics experience?" "Short distances" means 0.01 to 1 ...
James Strieter's user avatar

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