IR LED sensor in one Diode?

Hello guys,
I am not sure if this is the right forum to ask my question but I Will ask it anyway.
can we design a single chip diode that emits an infrared light and receives it? (not two diodes where one is receiving and the other emitting)? is it doable physically?

best regards

You want this to transmit and receive simultaneously? Or do you want the same diode to work as both an emitter and detector at different times?

Hi,

I know that some laser diodes include a "monitioring diode" to control the laser ouput power.

But I don′t know if there are IR LEDs. I′d try to search with the phrase "monitoring" or "monitoring diode".


Klaus

Sounds like you want the same light beam transmitted, being reflected from somewhere and stimulating back the diode. Even if it were possible from the circuitry or semiconductor's side, you should be aware that it is impracticable from the optical side. It would be needed an absurd distance so that the end of the transmitted beam did not coincide with the beginning of the received beam. Perhaps unecessary to say that dispersion would take place in such a ratio that you'd be lucky if one or two photons returned back to the exact spot where they left.

thanks guys for the quick reply. Yes, I want the same diode to work as both an emitter and detector at different times. i can say that I want that the diode behaves as the receiver at first interval of time and transmitter at the second interval of time from semiconductor's side.
ANdre, I agree with what you said but I want like to use on optical fiber line for one diode.
Klaust, I want that diode monitored for receiving at certain time and transmit at another time

I'm not a physicist, but this sounds slightly infeasible. A diode would be optimized for either transmitting or receiving; I suppose it's possible to create one that does both, but it probably wouldn't perform either function well. But, CMOS RAM can be used as an image sensor, so maybe there's a way to create a 'bidirectional' optical diode.

Sometimes we do not realize that a possibility exists until the matter is raised. Regarding the LED being used as a light sensor I had never thought about this possibility, but it really could be done:

https://wiki.analog.com/university/c...lab-led-sensor
https://www.sparkfun.com/news/2161

The only issue is how to implement a circuit that can handle both the sending and the receiving alternately, or simultaneously; In this case, if the distances involved in the length of the optical fiber are not in dozens/houndred kilometers range, the switching from the transmission to the reception circuit should be very fast.