Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [optical]

53 questions
15
votes
5 answers

Non-invasive bubble sensor

I'm trying to make a non-invasive bubble sensor. The liquid is going through a 3 mm plastic tube and the liquid is a clear saline solution. I believe the easiest solution is an optical method using a phototransistor and some kind of LED. What I've…
Bommersooner21
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3
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4 answers

Optical detection of a fan wheel

I want to detect the rotation speed of an impeller (fan wheel). Imagine a fan without a motor submerged in a liquid. This device is used for visual indication of liquid flow. I want to detect the rotation form the outside without modification of the…
sgt_johnny
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3
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2 answers

Using QSFP28 Module at Lower Lane Rate

I have an application that requires optical transmission of 4x16 Gbps SERDES lanes over fiber. A QSFP28 module for 100G ethernet seems like a great commercial solution--it can take the four lanes and combine them over a single fiber channel. The…
jalalipop
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3
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2 answers

Anyone got these optical encoders working?

I got these Optical Encoders from a local vendor and connected it to my arduino in the following order; (+)----> 5v (-)---> Gnd (01)--->2 (02)--->3 But, it burnt and smoked out as soon as I connected it. I am assuming it requires a current…
Samiul Hoque
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3
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1 answer

SMD LED: How to calculate optical power (in mW) from luminous intensity (in mcd)?

I chose an LED for my application but I need optical power, in mW. In the data sheet, luminous intensity is shown in mcd but I did not find formulas for calculation although there are graphs, etc. Where luminous intensity is 180 mcd and viewing…
Patrick19
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2
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0 answers

Approaches to creating better mouse pointing hardware for absolute input?

I play the video game osu!. Osu! is a game that requires the player to quickly move the mouse pointer to different areas of the screen in a precise manner. A game such as osu! lays out unique requirements for an input device: It should be absolute…
Árni Dagur
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2 answers

I've seen many conflicting answers online: For optical storage, does a pit represent a '1' bit or does a land represent a '1' bit?

I've seen many conflicting answers online so: When reading an optical disk, which one of these is true: A 'pit' represents 1 and a 'land' represents 0 or A 'pit' represents 0 and a 'land' represents 1
Tom
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2
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3 answers

Opto switch for detecting translucent polypropylene

I am building a liquid handler (a CNC machine that pipettes small quantities of liquids). The machine switches polypropylene "tips" between pipetting different fluids. Positional accuracy within 0.5mm of the pipette tips is key. However, I have…
David F.
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2
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2 answers

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 built as a prototype now except for the data…
Alex I
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1
vote
1 answer

Experiencing undershoot with OPA857 transimpedance amplifier

I am trying to amplify an optical signal which comes from a photodetector in the range of 30 µA with a transimpedance amplifier (OPA857) followed by a variable gain amplifier (THS7530). The problem is that the output is experiencing undershoot and I…
Farzin
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1
vote
1 answer

No light detected from 1310 nm IR optical transceiver AFBR-5813TQZ

I am trying to build a test application circuit for an AFBR-5813TQZ IR (1300 nm) optical transceiver. For now, I am only trying to verify that the transmitter works, so I have breadboarded the recommended application circuit from the datasheet, fed…
Ahmad
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1 answer

Transceiver VCSEL failure analysis

We've had a number of optical transceivers fail recently and I am trying to track down the cause. It has happened with two different models: HFBR-53A5VSEMZ (now obsolete), and the TSP-D1CH2-C11. Some have failed after 18 months in the field, and…
sbell
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Calculating minimum incident optical power when BER is given

I'm trying to solve this problem: A silicon photo-diode has a responsivity of 0.6 A/W at a wavelength of 850 nm. Determine the minimum incident optical power at the photo-diode at this wavelength in order to maintain a bit rate of \$10^{-7},\$ when…
Diana
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1
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2 answers

Optical filters: What is the difference between Free Spectral Range (FSR) and the resolution based on (FWHM)

I have a question regarding the Free Spectral Range (FSR) and resolution based on (FWHM) of optical filters like based on Fabry-Perot-Interferometers. As of now, I always thought of the resolution as the minimum spacing between two spectral peaks an…
Dakalaom
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1 answer

Measurement of output current of a photodiode

I am a German student. My task is to conduct a characterization of a photodiode (KPEIMC-UDCOM by Kyosemi.) The photodiode will be illuminated by 850-1550 nm laser diodes. It would be good (but not absolutely necessary) if I could do frequency…
Warlock123
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