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Questions tagged [photodiode]

A photodiode converts light to an electric current.

A photodiode creates a current proportional to illuminance when light falls on it. We distinguish between visible light and infrared (IR) photodiodes. A phototransistor integrates a transistor with the diode to increase sensitivity.

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How do I connect a photodiode?

I'm trying to design a circuit to measure the ambient visible light (380nm to 750nm). Accuracy isn't too important. I've been looking at photodiodes, but I'm not sure how to connect them up. I need the following requirements from my circuit: low…
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What does "case" mean exactly for this three-prong photodiode?

I'm very interested in measuring the the precise amount of amperage coming out of a Si photodiode for an experiment of mine while under illumination. We use Gamry potentiostats for these measurements. I'm looking to purchase a photodiode from…
Chris
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Ambient light rejection from photodetecting circuit

I've built a photodetecting circuit as below: simulate this circuit – Schematic created using CircuitLab And with this circuit, I'd like to measure brightness of a blinking LED: From the left, light pass through 500 nm shortpass filter and hit the…
Jeon
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Photodiodes: Measuring Low Optical Power vs Dark Current Contradiction

Taken from: http://www.geni-uv.com/download/products/GUVV-T20GD-U.pdf I'm trying to do some estimates here and I've run into something that seemingly doesn't make sense. In the table above, it states that the photocurrent is 14.7uA at 1mW/cm^2. To…
DKNguyen
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Current/Voltage Amplification and Photosensitivty in Photodiode

I have a couple questions related to the same home project. I am brand new to circuits and have just started reading into photo diodes. Q1: I have a home project goal to essentially get a photo diode to distinguish the different colors of LED lights…
Sophia
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Narrow bandwidth photodiode?

I'm working with robots that use IR sensors to avoid obstacles. In my experiment, I'm using a tracking system that uses IR leds at 850 nm. The problem is that the IR sensors detect the tracking system light and return wrong values. I am considering…
tguichaoua
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Photodiode current equation

The current in photo diode because of generation rate G and depletion width W is given as qGW (neglecting diffusion currents). When the light is incident on the diode excess carriers are generated in depletion region in pairs and these are swept to…
subhash subbu
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Photodiode selection for fluorescent probe

At the moment I am trying to build a DIY fluorescence detector using the Amplex Ultra Red probe with excitation and emmission maxima at 568 and 581nm respectively. I just have problems choosing the right photodiode. The photodiode will have to…
Felix
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Photodiode sensing circuit with inverted output

I want to build a photodiode light sensing circuit so that the output voltage is inversely proportional to the light intensity going to the photodiode. I.e less light equals more voltage. I'm thinking of a circuit like this: simulate this circuit –…
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Why some photodetectors have large areas?

Why some photodetectors (specifically Si pin PDs) have large areas? and how this large area affects on the figure of merits of a photodetector? Excuse me if the question is and general. I could not find good (answer and) references for my question.…
Mr. Nobody
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Characterizing Photodiode's angular response

I like to make a simple experiment to characterize the angular response of a particular photodiode. (SFH206K). Current thinking is to use a flat table, use a red laser, turn off the lights, point the laser to the photodiode at various angles and…
Frank
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Two identical photodiodes with same FOV but different active areas

Would two otherwise identical photodiodes (same silicon, same field of view) with different active areas illuminated by the same ambient source (ambient as in fills the entire FOV) produce different magnitude of output? To me it seems initially they…
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Does the responsivity change with temperature of a pin photodiode?

I have a more fundamental question on which I can not find any answer, maybe there is some inherent understanding I am missing. I am currently trying to evaluate the temperature behaviour of a InGaAs pin-photodiode. What I often find is that the…
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How to make MSM photodetector more selective?

I got a question, how can I make Metal-Semicondutor-Metal photodiode more selective in terms of wavenlength spectrum. I need to mention I cannot use Bragg reflectors like in RCE photodetectors. All I can use is quantum wells and p, n doping layers.…
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How to use photomultiplier tube

I am planning to buy a photomultiplier tube for my lab experiment but I am not sure how to use it exactly. For eg. I was looking at the hamamatsu HC-120-05. http://mi-lasers.com/wp-content/uploads/HAMAMATSU-HC120_series.pdf It is written in the…
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