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ArcticMyst Security by Avery

Help/advice needed with driver circuit to pulse IRLD at rf frequency

AXE

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Jun 24, 2011
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Hello everyone I'm hoping someone can offer advice on a project I've been working on for a while. Without going into too much detail, this project started as something very different and kind of by accident has arrived at lasers lol!

I have a (very?) basic understanding of electronics and need to build a circuit that is capable of pulsing an infrared LD at a frequency between 50MHz and 60MHz (to be decided). I envisage a bias tee setup that floats the LD at threshold (600mA in case of 1000mW diode) and superimposes a pulse waveform which drives the LD from threshold to full power and back again in less than 20ns. So far, it seems as though accurately switching that level of energy at that kind of frequency is technically challenging, so probably a big ask on a small budget??
Laser and PIN photodiode detector to measure output will be enclosed.

Goal:-
50-60MHz, ~50% duty cycle
800-850nm
LD choices: 300mW min, ideally 1000mW peak power
Pulse shape isn't super critical at this stage, I just want to get it to strobe and see what happens.

From memory, the 1W 850nm LD has abs. operating limits as follows: 2.2V max, 600mA threshold, 1200mA max.

Is this feasible and if so can anyone advise of or direct me to some kind of circuit capable of this?

Thank you 😁
 





Encap

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Joined
May 14, 2011
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This guy built a low cost 850nm pulse generator circuit: https://www.researchgate.net/publication/252252470_A_low-cost_high-repetition-rate_picosecond_laser_diode_pulse_generator

Maybe have a look here: http://assets.newport.com/webDocuments-EN/images/Pulsing_Laser_Diode_IX.PDF

and see article with image below from: http://www.jensign.com/opto/ledlaserdrivers/
monocircuit.jpg


And see thread "How to pulse a laser?" : https://laserpointerforums.com/f67/how-pulse-laser-70292.html

Hope those help.
 
Last edited:
Joined
Sep 12, 2007
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Why do you need a watt of IR laser at 50MHz? What exactly are you building or implementing?
 




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