Fiber optics is the study of optical fibers, which are thin pieces of high quality optical materials which are able to act as a waveguide for some frequencies of light. This waveguide or 'light pipe' feature of optical fibers allows them to transmit light with very low loss from one end of the ...

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fiber optic face plate physics-opaque to transparent behavior based on distance of object?

Please look at this video below. its of fiber optic plate or compressed fiber lens Here it seems that the object- which is the book or letters here, is visible only when the plate is touching the ...
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6 views

trouble calculating dispersion curve for TE Mode symmetrical step-index waveguides

I'm trying to work on a problem where I'm needing to show the dispersion curves for a slab waveguide. I'm given the refactive index of the core, $n_1$, the refractive index of the cladding, $n_2$, the ...
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28 views

What causes the bright glow on the edge of fiber optics and translucent sheets?

http://imgur.com/8PHxy6z On top of the picture, we have a number of translucent sheets. The edge of the sheets seems to glow compared to the rest of the body; why is this? On the bottom of the ...
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17 views

Fiber Optics - Mechanically Induced Long Period Fiber Grating

I created a grooved plate with a groove spacing of 650 microns which I used in an experiment to produce a mechanically induced LPFG(Long Period Fiber Grating). I measured the transmission spectrum ...
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22 views

How to calculate light transmission in dBm if it goes through SMF to MMF or MMF to SMF?

The question might be very basic, but I could not conclude it after thinking and searching about a couple of hours. If a light in fiber optics is launched in an SMF, therefore, it is connected to an ...
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72 views

Why do TM and TE modes coexist in glass fiber?

I have read that TM (transverse magnetic) and TE (transverse electric) modes of the electromagnetic field of light travelling in a glass optic fiber cable coexist. I want to know the precise ...
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35 views

What is the problem if we use air as clad in fiber communication?

The refractive index of air is approximately 1 and that of core possibly be 1.5. The refractive index of clad could be 1.48 or 1.45. The refractive index of clad and refractive index of air both ...
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108 views

Intensity fluctuations at the output of a single mode fiber coupled to a He Ne laser

I have coupled a Thorlabs HNL050L-EC - HeNe, 632.8 nm, 5 mW, Polarized Laser to a 2 meter long single mode fiber patch chord using a Thorlabs F230-FC-B aspheric lens. While I am certainly able to ...
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28 views

Why are photonics fibers called band gap fiber?

Why are photonics fibers called band gap fibers? Do the photonic fibers guide light inside the band gap or outside? What creates the band structure?
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38 views

Focal Length Calculation [closed]

Although I research in the internet, I couldn't find detailed answer. I have a question and I want to make sure from the answer. The ligth is coming from a fiber laser source and focused on a ...
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24 views

Deriving a spatial resolution formula for an OTDR (Optical Time Domain Reflectometer)

I'm trying to gain a better understanding of where the following formula comes from: $∆x= \frac{τc}{2n}$ Where ∆x is the spatial resolution, τ is the finite pulse width, c is the speed of light and ...
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19 views

Producing a collimated beam from a point source

I have an optical fibre of numerical aperture $NA$, of very small core radius, located at the focal point ,$f$, of a lens. I should produce a collimated beam of initial radius $f\cdot NA$. But what ...
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35 views

Is it possible to use a tapered fiber to collimate a single-mode light beam?

I would like to collimate a light beam stemming from a single-mode LED source. As the source is pretty big (a few millimeters), collimation with a single lens gives a bad result, i.e. a quite ...
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39 views

How do pulse properties relate to the pulse's peak power?

Let's say we know the temporal shape of an optical pulse, which is $E(t) = E_0 \cdot f(t)$, where $E(t)$ is the electric field, $E_0$ its amplitude and $f(t)$ the shape function (e.g. $sech^2$, ...
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44 views

Would the quantum state of a photon be disturbed if it were traveling through fiber optic cabling?

See here... https://en.wikipedia.org/wiki/Linear_optical_quantum_computing https://en.wikipedia.org/wiki/Optical_fiber_cable I'm just worried that upon reflection within the cable the photon's ...
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26 views

in fiber whats relation between nonlinear effects? [closed]

i only know when power light is more than threshold ,nonlinear is showed . why they called nonlinear?where characteristic is nonlinear,it is for me ambiguous. Self-Phase Modulation (SPM) Cross-...
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40 views

What happened to the perfect mirror?

Back in 1998 an article was published in Science by JPL's Jon Dowling claiming a method for making a perfect dielectric mirror: "Mirror on the Wall: You're Omnidirectional After All?" Jonathan P. ...
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61 views

Wave vector relation in nonlinear material

A light wave ($k_1,\omega_1$) travels in a medium of refractive index $n_1$ and then encounters a nonlinear medium ($n_2$) under the angle $\theta_1$. Snell's law tells us the wave's direction in the ...
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59 views

Coupling into FC/APC fiber

I am currently attempting to couple a 405nm laser diode into FC/APC fibre. The fibre is mounted on a flexure stage approximately 15.3mm from an f=15.29mm lens. I have managed to couple into the core ...
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31 views

Can you pass 400mJ laser light through a fiber?

What is the energy limit for fibre optics? For a dual-pulsed nd:yag laser firing at 10Hz with energy roughly 2x 400mJ, and pulse width ~5-10ns. My gut says that this is far too high to pass through ...
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128 views

Why is fiber coupling efficiency dependent on core diameter?

I read on Thorlabs' website that the coupling efficiency of a fiber is primarily dependent on the core diameter and numerical aperture of the fiber. It makes sense to me that if the beam of light ...
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39 views

Polarized light in single mode fiber

In single mode fiber the light propagates in two orthogonal planes. Input will be linearly polarized light, which state of polarization will be on output and why? And if there will be some different ...
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61 views

How to compare optical fibers of different material, NA and diameter

For an experiment I would like to figure out how different optical fibers behave in terms of losses at both ends and their attenuation for a given wavelength. Let's say, I have three different ...
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25 views

Ray transfer matrix analysis (Fiber)

I'm currently trying to read into ray transfer matrix analysis and am fiddling around with some of the exercises in the workbook. This one is especially annoying, since I don't know if my approach was ...
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28 views

Fiber holder with 'vacuum' holes.

I'm a student in my third semester and am currently working with workgroup in our physics department. Last week our lab got access to liquid nitrogen and we are fiddling around with fibers in ...
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23 views

Hollow metallic waveguides versus optical waveguides versus cables

In almost every physics program, you learn about electricity, electromagnetism, photonics, ... Within the electricity course, you learn about transporting electric energy as electrons through cables. ...
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27 views

Understanding hollow waveguides. What is $\lambda_g$ on the figure?

I am trying to understand the field distribution in waveguides. On the figure is $HE_{12}$ mode of hollow fiber. What is the $\lambda_g$ ? Is it $\lambda_g$ = $\lambda_0$ / $n_{eff}$. Does the z ...
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66 views

Which waveguide mode will be excited by circularly polarized laser mode $\mathrm{TEM}_{00}$ entering hollow fiber?

Linearly polarized Gaussian mode $\mathrm{TEM}_{00}$ mode, would couple into HE modes of circular hollow fiber. Which modes would circular polarized beam excite entering hollow circular fiber ?
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63 views

Attenuation and Amplification - Transatlantic telecommunications cable system

It's a german book so I don't know if I'm translating this properly into english, so bear with me: The TAT-14 connects the cities Norden and Tuckerton with glass fibers (~7500 km). The cable has ...
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52 views

Is there a beam splitter in time?

I have a train of pulses (with some known time separation between them) and I want to mix two of these (perform an XOR - beam splitter transformation - between them), leaving the rest alone. How do I ...
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23 views

Shaving down length of a GRIN lens to a desired wavelength

I have a GRIN lens that collimates light from a point source at 670nm. I want to shave the thickness of the lens down to use for 530 nm. I can't find anything useful for equations online. None seem to ...
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77 views

Total internal reflection in single mode fiber

As only one mode (parallel to the fiber axis) propagates through a single mode fiber, so does total internal reflection occur inside a single mode fiber and how? And how the light is guided in single ...
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112 views

Collimated light directly into a multi-mode fiber

This is my question - Will a collimated, incoherent light, consists of a limited angle, that "hits" a multi-mode fiber facet exit the fiber as collimated? (just to be clear, no lens is involved. I ...
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51 views

Using fiber optics to focus quartz tungsten halogen light

Our purpose is to make 1 mm spot size of quartz tungsten halogen light with 100 mm working distance for spectral imaging of wavelengths of 350-2000 nm. With some QTH light source and adapter on the ...
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1answer
191 views

Spectral Line- Width

How does the spectral line-width of light source (let that be ordinary light, LED, LASER etc.) decides for which communication purpose it will be used for ? Is it like spectral line-width effects the ...
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1answer
14 views

What is “Data point spacing” in fiber optics?

I was going through documents related to Optical Fiber communication. There to define optical fiber, parameter "data point spacing" is used. I tried googling, but there is no proper explanation any ...
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29 views

Principle of fibre optic cable coating

I was reading about fibre optic cables and it was mentioned that ,the individual "light pipes" are coated with a material whose refractive index is less than that of that of the glass. My question is ...
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35 views

Why would longer distance between collimated lenses improve coupling efficiency?

Im coupling 1550nm output from a single-mode lensed optical fiber to a standard SMF using a pair of collimating lenses, matched to the NA of the respective fibers. However, I find that by increasing ...
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31 views

Why does not the optical fiber break? [duplicate]

Glass is a very fragile object. So why does not the optical fiber break? Everytime I take them, I am worried about this problem.
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72 views

Why does some light escape when in a fiber taper?

I am working with fiber tapers and i noticed that some light escapes from the tapering region and i am quite curious. I am using a 500 micron plastic optical fiber and i managed to stretch the ...
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1answer
69 views

Why do higher modes propagate more in the cladding of an optical fiber than lower modes?

I am trying to understand the theory of inter-modal dispersion in optical fibers. It seems quite obvious that if higher modes have a greater angle of incidence in the fiber than lower modes, the path ...
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51 views

473 nm light through a single mode fiber designed to operate between 1500 and 1600 nm

Can we send light with 473 nm through a single mode fiber designed to operate between 1500 to 1600 nm spectrum? The radius of the fiber core is 4.25 micrometer, NA=0.12 and the single-mode cut-off is ...
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1answer
468 views

How I can launch light into PM fiber

A polarization maintaining fiber preserves the linear polarization of the light at the output, the light at the input must be linear polarized to see signal at the photodetector... However I can't see ...
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309 views

Calculating the beating length of the directional coupler

I want to determine the coupling length needed to achieve a certain power coupling coefficient of a directional coupler. Recently, I read a paper titled "Ultra-compact high order ring resonator ...
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1answer
1k views

What will happen if I transmit 850nm signal through a 1300nm optical fiber? [closed]

We prefer 1300nm optical fiber over 850nm optical fiber because later one is more efficient. So am selecting 1300nm optical fiber. But I want to know the possibility of using same cable to transmit ...
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1answer
56 views

How can I make an optical circulator?

I need to a single mode 1550 optical circulator at my lab. I have a varied supply of components, but no circulator. Any idea how I can make one myself? Perhaps using coupler and isolator? Thanks. -D
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220 views

Snell's law demonstration

I'm a bit confused about a Snell's law demonstration. I'm reading Communication Systems from W. Tomasi. In the chapter 11, the author applies the Snell's law to θent, and -here comes my problem- he ...
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379 views

Will microwaves interfere with data transfered through fiber optics?

Do fiber optical cables used for broadband signals of Internet get any interference due to any nearby microwaves generated in mobile phones? I learned that fiber optics are used to transmit data in ...
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197 views

How to calculate the Gain of EDFA amplifier? [closed]

I have co-propagating pump laser and tunable optical signal and I want to measure the Gain of EDFA Amplifier from the Optical Spectrum Analyser (OSA). I have measured first the signal power without ...
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1answer
78 views

Will light leak into a side glow optical fiber?

I am looking into some possible applications of side glow optical fibers (plastic). Will side glow fibers "drive" adjacent fibers? That effect is undesired.