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can laser be used as a frequency source for a photodiode which can act as a transmitter/oscillator? Answered

photodiode induce current when a light of paricular wavelenth/frequency  strikes on them..laser have a high frequency and low wavelenth......instead of light but electromagnetic waves,can it act as a source of frequency on photodiode hence making a oscillator????

Tags:laser

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steveastrouk

Best Answer 7 years ago

What a neat idea. Unfortunately we have very few, if any, components that can switch at optical frequencies ! You would be looking for somehing that can switch at 1015Hz ! Beyond state of the art, or at least commercial state of the art.

Steve

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arihant

7 years ago

well, my idea is '
transmitter
laser -------------------photodiode-------------antenna
laser can be swtiched in and off.

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arihantsteveastrouk

Answer 7 years ago

but the transmitter and receiver will be having same frequency and we can change the amplitude by changing the current in the laser.....isn't it?

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steveastroukarihant

Answer 7 years ago

Are you attempting to modulate the laser amplitude or what ?

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arihantsteveastrouk

Answer 7 years ago

steve,don't get frustrated with my continuous questioning...
i will change the amplitude of the circuit by changing the current of laser..hence changing the resistance of photodiode
and current in the receiver will also change ....this is an idea only...i will try to make it in this month....

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steveastroukarihant

Answer 7 years ago

There seems to me to be no point using a laser to induce changing current in a photodiode, to drive an antenna, since you still have to change the amplitude of the laser at Mhz rates, and you may as well just drive the tranmitter directly.

Steve

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arihantsteveastrouk

Answer 7 years ago

thanks for ur suggestion..and reasoning.....:)

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lemonie

7 years ago

(This is hard to understand)
Lasers do not necessarily have high frequency and low wavelength (relative terms anyway) and light is electromagnetic waves.
Steve' has your best answer.

L

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frollard

7 years ago

no, the diode picks up that frequency and conducts accordingly. If you modulate (pulse) the laser on and off, then the diode will show that same pulse on the other end.

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orksecurityfrollard

Answer 7 years ago

+1. The question confuses the frequency of the light (which drives the physics of the photodiode) with the frequency of a signal (which, as Frollard says, would be explicitly imposed on the light beam).