Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [optoelectronics]

Components, circuits, or systems that convert between electrical and optical (light) energy.

Optoelectronics deals with electrical interfaces to light sources and/or light receivers.

Optoelectronics are often used in control circuits where electrical isolation is required between the source and the receiver (optocoupler) or to convey visible information to a human (LED).

Since optoelectronics is a broad topic, it makes sense to also include some lower-level tags as part of the question. Some examples:

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How do I model an LED with SPICE?

What diode modifiers are used in practice to model LEDs with SPICE (Berkeley v.3f5)? These are available to me: # Name Parameter Units Default Example Area 1 IS Saturation current A …
tyblu
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Is it possible to generate light with an antenna?

An antenna (e.g. a dipole) is able to radiate at a certain frequency thanks to the EM field generated by a current provided by a signal generator at such a frequency. So, for instance: Voltage source at frequency f (representing an amplifier) +…
Kinka-Byo
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How does a 40 Gbit/s Ethernet interface process packets in silicon?

A 40 Gbit/s Ethernet interface should have a 40 GHz signal on it. How does common silicon IC technology handle such an exotic beast? My best guess is that internally various parallel busses are used, but I haven't found much on the internals of…
Watson Ladd
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Why does the intensity of light in LEDs not increase with current after a particular value?

I read in books that light intensity from an LED does not increase beyond a certain value of current. The amount of light emitted depends on the combination of holes and electrons. If so, then as the electron flow increases in the circuit, the…
Andrew Flemming
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How does a 4 pin RGB connector work without ground?

The question is in title. Why there is no ground pin on the 12V RGB header? The 5V ARG header which uses only 3 pins has a ground. How does it work without a ground?
DEKKER
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Why do Infrared LEDs come with different coloured lenses?

I'm just starting a project to build a universal Engineer's Remote Control Unit [EG. able to send the Panasonic 0xF2 code, etc.]. I have seen that IR LEDs come with (at least) three distinctly different coloured lenses, namely "Crystal Clear",…
BlueChip
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Measure power supply ripple with Rigol DS1052E

I recently received (as a birthday gift) a Rigol DS1052E oscilloscope. I read about oscilloscopes but I never really used one. So my question is: How can I measure the ripple voltage of a floating linear power supply, using this oscilloscope? Can…
Buzai Andras
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Using a LED to transmit data

I am curious about the possibilities offered by LEDs to transmit data over a short range (2 or 3 meters), and what maximum data transmission rate can be expected from carefully chosen, but consumer-grade components. I am interested in a minimal…
oparisy
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How can we explain this strange phenomenon with an optocoupler switching?

Two optocouplers are connected according to the circuit below. The input voltage across the first optocoupler is a true square wave (3.3 V amplitude). The first optocoupler is an open collector output and the second one is an open collector…
Tommazo
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What is the purpose of using an analog optocoupler?

What's the purpose of using an analog optocoupler in this circuit? Why not a digital one? An industrial battery charger. Normal operating voltage to monitor ranges from 120 V (Battery low) to 180 V (battery fully charged)
albatross
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Ham Transceiver to computer Interface design question

I am building a Ham transceiver to computer interface, which has the RS232 port controlling the PTT on the radio. The circuit currently calls out for a 1.2K resistor in series with the RTS line and the 4N25 optocoupler's input. If I use a 4N35…
Chipresistor122
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How does an optical mouse detect movement?

Can anyone explain it ?
fms
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How to detect glue without surface contact

I am currently working on a project that requires a section of "release liner" to be removed and a clear plastic to be put in its place after a few holes are punched out of the paper. What I am trying to figure out is how to detect if the plastic…
Friendlyghost89
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Using an Opto-Isolator to detect 120VAC on a Microcontroller

I am designing a system where I need to know whether or not 120VAC is present on a specific wire. The system is in line with a fuel pump system, and I need to check to see whether or not the pump is getting power, if not, make an alert that the…
Matt Clark
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Typical wavelength range for solar cell measurement

Why is a wavelength range of 300nm-1100nm usually used to investigate the properties of solar cells (EQE, current generated, etc.)? Is it to reduce spectral impact? I also don't understand what is meant by spectral impact...
Jin Yi
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