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I have read recently somewhere which I cannot find now, that extreme short pulse width lasers cannot be generated electronically.

But if electronic circuitry is not capable to to generate such laser pulses, how is the pulse width of them measured and recorded by a device(which is also made up of electronics)?

floppy380
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    https://www.brown.edu/research/labs/mittleman/sites/brown.edu.research.labs.mittleman/files/uploads/lecture14.pdf – The Photon Nov 12 '20 at 01:15
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    @ThePhoton Damn that's good reading! I love it. – jonk Nov 12 '20 at 01:19
  • @jonk, I don't know enough to answer the question, but I know what to google. – The Photon Nov 12 '20 at 01:22
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    @ThePhoton Well, I'm going to siphon down what I can. Lecture 13 isn't new material, but nice too. But I really loved the hit you got. It's written from a clear perspective and helps any of us know how we know what we know is true about the world and provides a beautiful example. It's applicable to anything we use that makes measurements. For a voltmeter there is theory, experimental result, and observation. But underlying some theory, there are still more prosaic theories, experimental results, and observations. Etc. "All the way down," until we reach some unchallenged axioms we assume. – jonk Nov 12 '20 at 01:30

1 Answers1

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I have read recently somewhere which I cannot find now, that extreme short pulse width lasers cannot be generated electronically.

That is correct, for femtosecond and shorter pulses, techniques such as mode-locking are used to generate pulsed output.

In mode-locking, nonlinearity in the laser itself is used to spontaneously generate pulsing.

But if electronic circuitry is not capable to to generate such laser pulses, how is the pulse width of them measured and recorded by a device(which is also made up of electronics)?

Pulse width of short lasers is most often measured using an autocorrelator, where the pulse is compared to a time-delayed version of itself using a nonlinear medium. See optical autocorrelation.

user1850479
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