Questions tagged [optical-fibre]

A flexible, transparent, fine fibre made of extruded silica to function as a wave guide to transmitting signals through light

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1answer
49 views

Photodiode not working in reverse bias

I'm using a photodiode module, model: coaxial InGaAs, Gtel. I set it in reverse bias with 5V and tested it with a laser but it doesn't give any output voltage. Unfortunately I don't know the laser ...
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2answers
49 views

How optical sources having narrower spectral width gives higher data rates?

How optical sources having narrower spectral width '\$ \Delta \lambda \downarrow \$' gives higher data rates '\$ R_B \uparrow \$'? For example: Laser having lower spectral width gives higher data ...
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1answer
142 views

LED strip appropriate for fiber-optic cables

A project will use 20 fiber optic side-glow cables, 3mm-thick, with one controllable LED each. A WS2812 LED strip or similar would be perfect for the ease of controlling the LEDs, however all that I'...
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1answer
61 views

A few questions about the application of ethernet controller and PHY chip and SFP module

I have a question about the connection/application between the ethernet controller and PHY/SFP modules. Actually, there're so many scenarios for building up a NIC card, which makes me confused. For ...
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1answer
79 views

optical glow fiber for low-tech communication links?

Can cheap "glow" optical fiber (or other inexpensive materials such as aquarium air tubing, etc.) be used for low-tech low-speed optical communications using just simple discrete components, such as ...
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4answers
600 views

How to make affordable DIY low-res absolute rotatory optical encoders with fibers? [closed]

I have zero knowledge of optics and want to make a very low resolution (~10°) absolute rotary optical encoder using rapid manufacturing (I have 3D printers, laser cutter, and desktop CNC). Digging the ...
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0answers
27 views

How to measure the amount of light emitted back from a fiber optic cable?

I would like to build a setup where I use a light source to emit a signal over a fiber optic cable, and then measure the amount of light that is emitted back, e.g. by blocking/opening the other end of ...
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46 views

How to Work with a Optical Fiber Ribbon

I got a piece of fiber optical cable that is in the form of a "ribbon cable" (see pictures). I have seen tools and procedures for making connections on a single strand of optical fiber. I would like ...
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1answer
54 views

Nanopower Fiber Optics / MOSFET Switch

I'm a newbie at designing at the nanopower level, hence my question. In this circuit, I have plastic fiber optical inbound signal that drives D1 photodiode, whose dark current is extremely low (tens ...
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1answer
74 views

Do electronic fiber optic selector switches exist?

From my research, I have been having a tough time finding and specifying a fiber optic selector switch or multiplexer. Do fiber optic selector switches exist? Background - Simple I have an ...
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1answer
37 views

How does a fiber optic receiver converts the optical signal to an electrical signal

A fiber optic receiver needs to convert the incoming optical signal to an electrical signal so it can be sampled. How is this achieved in practice? I believe a photodiode is used, but would a ...
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67 views

Switch DC/DC Converter through Fiber Optic Signal

I need to send a signal through fiber optic to switch a DC/DC Converter (I want it to be on when there is photocurrent, and off when there isn't), I can't use a normal cable because I want to do that ...
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1answer
28 views

Multimode to singlemode optic fiber

I'm naive in this field, but I will need to use optic fibers for optogenetics application. I already know that my question will sound stupid for the most of you, please forgive me for that. My ...
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1answer
45 views

How come optical data modulation is faster than that of electrical modulation while optical modulation is done by electricity?

why optical data is of high bandwidth that that of electrical copper data bandwidth when we use electrical signal to achieve optical data modulation ?
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1answer
39 views

Optical receiver output voltage higher than power supply

The part is a optical receiver from Broadcom. It has TTL output, but specified with a maximum output-high voltage higher than the power supply. I wonder what's special structure internal may make it ...
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1answer
914 views

Optical bandwidth and electrical bandwidth

I understand the concepts of electrical and optical bandwidths, but I encountered an example problem that used the following formula to calculate the electrical bandwidth: $$electrical bandwidth = 1/\...
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1answer
30 views

Shot noise variance of a channel for different bits

I've come across a question, where I had to calculate shot noise variance calculations of an optical link. As per the definition, shot noise in an optical channel is the current that arises from the ...
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1answer
71 views

Material dispersion in fiber optics transmission

In plain English, why does material dispersion increase with wavelength in fiber optic transmission? I am aware that refraction index decreases with wavelength increase, i.e. pulse travels faster, but ...
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1answer
61 views

How cell sites work? [closed]

In Mobile communication, how do cell sites communicate to each other to the point when they reach the cell site which is connected to the other mobile phone when I make a call . What is the medium of ...
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2answers
895 views

Using SFP modules from a microcontroller

I'm interested in having an embedded device send data optically. This is for test and measurement, where having conductive cables is problematic since it will perturb the measurement. The device is ...
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4answers
181 views

Fiber-optic transceiver ICs for applications other than fiber-optic Ethernet? [closed]

When we talk about fiber-optic transmission, we almost always talk about copper to fiber-optic Ethernet conversion using fiber-optic transceivers. But since fiber-optic communication is just ...
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6answers
7k views

Does Fibre Optic Cabling have any potential for noise?

After Google searching "Do Fibre Optic Cables attract any noise", most results return that they attract virtually no noise. Is this the case or are there some exceptions?
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1answer
37 views

differences between photelectric amplifier and optical amplifier?

i'm researching about fiber optic sensor and stumbled upon a question regarding about the amplifier. I've read in the internet that optical amplififer contained many type such as EDFA,semi-conductor ...
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3answers
8k views

Convert dB/km to /km

please explain How is 0.22 dB/km equal to 0.0507 km^(-1) I tried doing 10 log x = its value in dB but it doesn't work here
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4answers
17k views

What is the advantage of optical TOSLINK over RCA coaxial cable?

A popular standard for the transmission of digital audio between audio devices has been the AES3 standard (also known as S/PDIF). The standard sends stereo PCM audio and of often found in consumer ...
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1answer
1k views

Media converter (eth/fiber) problem in communication

I have a system which looks like that: CPU(macbook)<-->thunderbolt<-eth->ethernet media converter<-fiber->ethernet media converter<-eth->raspberry pi 2. Both CPU and RP2 have static IPs. ...
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0answers
150 views

Low cost low speed fiber optic connection for embedded applications

I would like to use a fiber connection to send data between two nodes. The nodes would typically have a 8 or 32 bit micro controller. I need data rate of 2 Mbps or higher and distance is about 100 ...
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1answer
160 views

What can i use an oscilloscope for in terms of networking [closed]

as someone who is just getting their feet wet in networking (going for a+ cert currently and would like to go further,) ive noticed that oscilloscopes can be used to monitor... seemingly any ...
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1answer
127 views

Direct connection between two SFP+ cables [closed]

I have been reading a lot about modern fiber networking recently and I have a clarifying semi-hypothetical question: Imagine I have two 3-foot sections of Multi Mode Fiber, and four SFP+ 10G ...
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5answers
6k views

Implement send-only (one-way) Ethernet cable

I want to build a unidirectional comminucation. In transportation layer of this device, it needs a one-way media to send data from side A to side B. All commercial products use SFP. I tested some SFP ...
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1answer
30 views

Auto Configuring Circuit Routing

This may be a little hard to understand. I have little knowledge in electronics, but I had an idea about optical fiber for data transfer, as far as I understand, ports/inputs/terminals/pins must be ...
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1answer
228 views

How Gigabit Ethernet is achieved in fiber optics?

I understand how 1000BaseT works on Cat 5 cables: It uses clock rate at 125 MHz, 4D-PAM5 data encoding to transmit 2 bit per cycle and it uses the four pairs of the cable. The math is quite simple: ...
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3answers
7k views

How is 255 Tbit/s processed in optical fiber communication?

I have never understood how the new record breaking data transfer speeds are achieved in terms of converting from/to electrical and optical signals. Suppose we have 255 Tbits of data and we want to ...
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0answers
120 views

How to use Arduino Uno to Process Signal from Leuze LV463 Optical Fiber Sensor

I'm attempting to use an Arduino Uno to receive the output from a Leuze LV463 Optical Fiber Sensor, but I'm a little confused as to which pin to use on the Arduino. The thing that is throwing me off ...
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0answers
60 views

Place of matched filter in fiber optic communication

In short-haul communication via optical fibers, we use photodiodes (PD) to detect the light. So if we want to use a matched filter, should we use it before the PD (optical domain) or after the PD (...
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1answer
120 views

Symbol rate and optical bandwidth relation

I am quite new to the field of optical communication, so perhaps this question is so easy. In reading some papers I have faced to the concept of optical bandwidth. For example, they say the symbol ...
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3answers
520 views

What does bandwidth mean in general, and in the context of the following examples?

Some examples : 1.The bandwidth of an operational amplifier 2.The bandwidth of a transmitted amplitude modulated signal 3.The bandwidth of a signal used in coaxial cables / optic fibre cables 4.The ...
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2answers
1k views

what is the span of an optical fiber?

I am new to the fiber-optic communication systems, and in reading some relevant papers, I faced to the term "span length" (such as long-span link) which I cannot distinguish it from the length of the ...
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1answer
129 views

How to drive a HFBR-1541 optical transmitter?

I want to drive a HFBR-1541 optical transmitter (see page 7; 60mA output current), and I want the driver to have extended operating temperature range (at least starting from -20 degrees Celsius). The ...
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1answer
234 views

How to implement serial-to-fiber optic Ethernet with WIZnet W5500? [closed]

I'm using W5500 to implement a serial to Ethernet converter, but I need to transmit over fiber optic cables. I will have a TX cable and a RX cable. How can this be done since the output of W5500 is ...
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1answer
2k views

C-Band in Optical Fiber Communication [closed]

I've read that the C-Band used in optical communication ranges from 1530 – 1565 nm. Since one nanometer corresponds to 0.000000000299792458 GHZ, this is far less than 1 GHz. However, the C-Band is ...
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1answer
120 views

How are the frequencies in 50 GHz channels in DWDM networks used?

In optical DWDM networks, the spectrum is classically divided into several 50 or 100 GHz channels. So, let's assume some channel ranges from x to x+50 GHz. On which frequency/frequencies is the ...
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1answer
95 views

Fiber transceiver operation

I recently bought a SFP fiber transceiver module to play around with. My idea was to connect the transmitter pins to a waveform generator, loop the optical output to the optical input with a fiber ...
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1answer
408 views

How to determine point of failure in photodiode circuit

I have a photodiode circuit which uses a fiberoptic pigtail photodiode as shown in the picture below: The photodiode is connected to an opamp as in the circuit below: The supply rails for the opamp ...
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1answer
660 views

What wavelength will achieve higher speed in optical fiber?

I've got quite easy question (and my attempt to solve it). So there is an optical fiber with Dispersion index: D = -100ps/nm•km, length: L = 10km. The question is: which wavelength will achieve faster ...
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2answers
483 views

Long Distance Wired Data Connection

I am working on a project where I am going to need long distance communication and I am unsure the best way to go about it. I am mainly trying to decide between fiber optic or Ethernet and decide some ...
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1answer
368 views

What is used to detect light from fiber optic signals in high speed Internet?

I'm curious, do they use photodiodes or something? As far as I know, that would be the cheapest way to do high speed communications over fiber (fibre? I'm 'murican) but I'm not sure.
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5answers
5k views

Why does a longer fiber optic cable result in lower attenuation?

I just carried out an experiment in my college to study the attenuation of fibre optic cable versus length and type of cable. This experiment was carried out with an LED light source and a power ...
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2answers
72 views

What options do I have to combine and format 18 600Mbps ADC serial streams over QSFP+?

The 18 serial streams are not encoded or scrambled. The idea is to multiplex them onto one or more encoded serial streams at higher rates for onwards transmission over optical fiber.
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2answers
141 views

Complete fiber optic transmitter and receiver with standard fiber optic connector and integrated power circuitry? [closed]

I am having a very difficult time trying to find a simple, completely self-contained module to convert digital signals (<2Mbps) to fiber optic, that uses a robust, standard fiber optic connector (...