Coherence describes properties of correlations among physical quantities of waves, with special emphasis on constant phase differences and frequencies in common. Such collective linkages enable stationary (temporally and spatially constant) interference.

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Spatial coherence of SLED light (width of active region?)

As far as I know, super-luminescent diodes (a.k.a. SLEDs) have a very similar structure to laser diodes, except that the front faces of the active region are tilted to prevent the sort of reflections ...
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308 views

Fiber optics with broadband, incoherent light

I wonder if someone could help clarify waveguiding with broadband, incoherent light please. If we take a telecomms fiber, which is single-moded above ~1.4 μm and couple a laser beam in, we assume ...
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What makes the radiation behind slits coherent?

Have a look on the sketch To get such a intensity distribution of light behind a slit we presuppose that all the light that moves on the two lines is coherent; of the same wavelength AND the same ...
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How can I simulate two fluorophores with a reticle?

Fluorophores typically emit in an incoherent fashion. I thought I could simulate two fluorophores (e.g. single molecule fluors) with a reticle. My concept was to make two small holes in a chrome ...
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37 views

“Classical” Coherence

I'm having a couple of courses where the concept of coherence is quite important. I know the traditional definition of coherence and it's connection to the phase of a wave. But often, I found, that ...
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What is the shape of the MTF curve in coherent imaging?

For incoherent imaging, the shape of the diffraction-limited MTF curve would look roughly like a triangle, with normalized contrast starting at 1 for zero spatial frequency and decreasing to 0 at the ...
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How is the temporal coherence of a pulse defined?

I am having problem with the concept of coherence and photon degeneracy. The temporal coherence of pulse is defined in Born and Wolf as: $$t_c=\lambda^2/c\Delta\lambda$$ (The time a photon takes to ...
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Understanding quantum coherence in biological processes (Magnetoreception)

Moved my questions to the top. Context below. Why is the strength of the electric field and the coupling constant being compared to the inverse coherence time? What is the inverse coherence time? Is ...
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Polarized Coherent Beam Hits a Polarizer Off-Polarization Angle While Varying Distance?

Just wondering about an experiment that should be easy to perform on an optical bench: A coherent beam is polarized. It then hits another polarizer which is set to permit a polarization angle off ...
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What is the relationship between coherent states and quantum coherence?

What is the relationship between coherent states and quantum coherence? To me coherent states were only talked about in regard to Quantum Harmonic Oscillator, whereas coherence and decoherence on the ...
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coherent length measurement of a monochromatic laser source

i need to learn about how to measure coherent length of a monochromatic laser source.I know that I can use michelson interferometer or spectrometry.For laser which has long coherent length michelson ...
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Are “phase-specific” masks ever used in the context of double exposure lithography? Can these sorts of things exist?

I was recently reading an 08' paper on double exposure lithography: and I was wondering if there existed some material that could be used to create a mask for e.g. a 193 nm light source that was only ...
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Finding the appropriate fitting function for a coherence length measurement

I'm studying Coherent Optics in Experimental Physics, and I intend to determine the coherence length of a two beam interference. To do that, I used an He-Ne laser, a Michelson interferometer and a ...
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Connection between coherence and monochromaticity of a light source?

Is there any connection between the coherence ( length, time ) and monochromaticity of a light source?
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65 views

Can thermal states of light be monochromatic?

As one can read from the quantum optics textbooks each mode of light of a certain frequency, spatial configuration and polarization can be considered as a quantum harmonic oscillator. One can imagine ...
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62 views

Coherence theory and spatial/temporal coherence

I'm working on a beyond the Standard model (BSM) experiment (on its theoretical side, actually) and I really need to understand better the concepts of spatial and temporal coherence. The rough idea ...
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34 views

Micro gripper for conveying tiny objects

Figure below shows a micro gripper used for conveying very small objects (i.e. the spherical object in Figure) and putting them in desired place using capillary force principal in a liquid bridge. To ...
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How to modulate the coherence of light field?

I want to use a Ronchi grating to modulate the coherence of incoming light field. The grating is placed at the object plane of an optical system under test. So can anybody answer my question about ...