All Questions
Tagged with optics interferometry
161
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When building a fiber optic interferometer what methods are used to reduce microphonic effects?
When building a fiber optic interferometer what methods are used to reduce microphonic effects? I'm familiar with a few methods such as: enclosing the interferometer under a sound dampening cover, ...
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Are there any commercially made optical fibers which are made specifically to have very low microphonic properties for application in interferometry
Are there any commercially made optical fibers which are made specifically to have very low microphonic properties for applications in interferometry. While building a fiber optic interferometer I ...
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Why laser output power fluctuates after passing through two 1x2 fiber optic couplers?
When laser source is launched into two 1x2 50/50 fiber optic couplers connected as below the output power constantly fluctuates in range of 70 uW.
The fluctuation happen roughly one to two times per ...
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Michelson interferometer but with 1 arm (Part 2)
I designed a setup similar to Michelson Interferometer but with one mirror only. So, there is an angle between the 2 rays to the detector:
In order to understand the result on screen, I used (Zemax/...
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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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57
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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?
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47
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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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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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53
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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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134
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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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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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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 ...
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58
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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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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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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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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?
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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 ...
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2
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185
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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 ...
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399
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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 ...
- 613
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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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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 ...
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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, ...
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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 ...
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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, ...
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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 ...
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Significance of the eigenvectors and eigenvalues of an interferometer?
An interferometer acting on $N$ modes can be described in terms of an $N \times N$ unitary transformation $U$ acting on the creation or annihilation operators of the modes.
I'm wondering if there is ...
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3
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Measuring coherence length with the Michelson Interferometer
In lab, I've been asked to measure the coherence length of a green-light laser source using a Michelson Interferometer. To do so, I configure the interferometer such that a circular fringe pattern ...
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2
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How many fringes can pass by on a Michaelson interferometer?
A Michaelson interferometer is an instrument that most physics undergrads get to play with once or twice.
A beam splitter sends part of the light to each of two mirrors, the light returns, then hits ...
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What is a 'good' coherence/correlation function for multimode spectra?
Following up on the question here and this answer in particular, I would like to pose the following question:
How to derive a formula for the coherence length of a multispectral source, such as a ...
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