Can a laser be used as an antenna?

Can a beam of any type extend transmission distance of an electromagnetic field?


  • $\begingroup$ Can you please explain what you mean by "Electricity can travel along a laser below"? $\endgroup$ – Mike Waters Feb 22 '19 at 21:10
  • $\begingroup$ I used to be very good friends with the late Bob Manor, a scientist who worked for a company called Energistics in Ohio, back in the late '70s or early '80s. They developed a technology for superimposing a 13 MHz radio signal on a laser beam. (The company broke up due to infighting between the two owners.) Is this what you are talking about? $\endgroup$ – Mike Waters Feb 22 '19 at 21:14
  • $\begingroup$ None of your three questions make any physical sense. I'm afraid there's nothing to answer but "No, and asking that makes no sense". Please ask something based on your current understanding of physics, not based on sci-fi fantasies! $\endgroup$ – Marcus Müller Feb 22 '19 at 21:15
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    $\begingroup$ @MikeWaters I won't be putting Muze down here, but his/her grab on physics is so slim that the electronics stackexchange site had to suspend Muze's account because he was flooding the site with questions of exactly this type: vague questions that strongly indicate OP hasn't understand the basics about what they make hypothetical speculations about. I'd very much like to be proven wrong, however! In any case, these are three separate questions, and OP should focus on one, imho, and explain where it's coming from! $\endgroup$ – Marcus Müller Feb 22 '19 at 21:27
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    $\begingroup$ @MarcusMüller Oh really? Okay. :-) In any case, this got my attention because I've never heard anything about that original invention since. Thanks. $\endgroup$ – Mike Waters Feb 22 '19 at 21:29

Light waves and RF waves are both electromagnetic radiation. The only difference is that we can see the narrow band of frequencies that we call light.

There is a common misconception that laser irradiance does not follow the inverse square law that describes the irradiance of an antenna. But in fact, they are exactly the same. The only difference is that the laser has a huge boost in initial intensity compared to an antenna. But thereafter, the laser irradiance decays following the same inverse square law.

The stark difference in initial intensity and the much higher frequency of the laser compared to typical RF systems makes it an attractive candidate to use for long distance, high speed communications. These facts have not escaped NASA's and the JPL's attention. An experimental system, dubbed OPALS (optical payload for lasercom science) has been used to transmit images from a ground station to the ISS.

OPALS used a simple 50 megabit OOK (on off keying) modulation with a forward error correction code to transmit video files. The signal is therefore a 50 MHz modulation of a 1,550 nanometer carrier. No different than an RF transmitter other than the use of much higher frequencies.


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