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Old 1st Apr 2019, 11:13 am   #12
Panrock
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Join Date: Feb 2005
Location: Worcestershire, UK.
Posts: 2,535
Default Re: Television over a light beam

Quote:
Originally Posted by rambo1152 View Post
back on topic though, are semiconductor laser diode too slow compared to LEDs?
I have limited knowledge of laser diodes. The answer all depends on the driver circuitry, which also should give protection - the bare diodes seem awfully fragile and easy to blow. Like LEDs, they should be current-fed to modulate them, but with L/Ds there are strict limits - step outside their parameters and you get no second chance. If you just take a laser pointer/pen you can modulate them to some extent by just varying the rail voltage, but yes... this will then be slow.

If I had been able to use a laser instead of a (rather special) LED for my 60MHz dem, the range would have been effectively unlimited. As it is, the range is set by beam spread from the transmitting condenser lens.

Steve
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