Can a laser work forever if constant electricity is provided? If we take a laser and provide it with constant electricity will the reactions in the semiconductor generate photons forever?
$\begingroup$
$\endgroup$
7
-
1$\begingroup$ Electronic components wear out, due to a number of mechanisms. One is simply the migration of atoms across the P-N junctions, due to a sort of "diffusion". Another is a rather bizarre "erosion" that occurs in integrated circuit wiring at the corners, similar to how "oxbow bends" form in rivers. But in most real cases these effects are vanishingly small and mechanical failure (due to vibration & thermal stress) and the failure of, eg, electrolytic capacitors are far more significant. $\endgroup$– Hot LicksCommented Apr 15, 2015 at 12:02
-
$\begingroup$ @HotLicks I suggest you make this an answer. $\endgroup$– garypCommented Apr 15, 2015 at 13:25
-
$\begingroup$ Nothing works forever... $\endgroup$– MithoronCommented Apr 15, 2015 at 13:45
-
$\begingroup$ @Mithoron What if i create a vacuum around inside the laser body? I think it will not wear as its not coming in contact with oxygen. $\endgroup$– BhaveshCommented Apr 15, 2015 at 15:21
-
$\begingroup$ @HotLicks What if i create a vacuum around inside the laser body? I think it will not wear as its not coming in contact with oxygen. $\endgroup$– BhaveshCommented Apr 15, 2015 at 15:21
|
Show 2 more comments
2 Answers
$\begingroup$
$\endgroup$
2
Theoretically yes, the laser principle does not consume any material. There is a light source that excites the electrons in the material to higher levels, they deexcite to some intermediate one, here the avalanche of photons appears producing the laser light and leaving the electrons in the ground state. And you can repeat the process without a loss.
-
$\begingroup$ Thanks you very much. Honestly i wanted to rate correct both answers but was not able to do it. $\endgroup$– BhaveshCommented Apr 15, 2015 at 15:14
-
$\begingroup$ What if i create a vacuum around inside the laser body? I think it will not wear as its not coming in contact with oxygen. $\endgroup$– BhaveshCommented Apr 15, 2015 at 15:21
$\begingroup$
$\endgroup$
3
theoretically if its components never wore out then yes.
however in practice things do wear out eventually and so no it could not be done in the same way that a perpetual motion machine can work in theory but not in practice.
-
$\begingroup$ Thanks you very much. I rated jaromrax's answer correct because he explained me in much detail. Your answer is also perfect so i appreciate your answer too. Honestly i wanted to rate correct both answers but was not able to do it. Sorry :) $\endgroup$– BhaveshCommented Apr 15, 2015 at 15:12
-
$\begingroup$ What if i create a vacuum around inside the laser body? I think it will not wear as its not coming in contact with oxygen. $\endgroup$– BhaveshCommented Apr 15, 2015 at 15:21
-
$\begingroup$ @Bhavesh It will wear out anyway. It's not oxygen that kills p-n junction, it's current-induced diffusion of ions. That will occur always when there is current through junction. It's also main reason why CCD matrices degrade with prolonged use. There the current is -like in p-n junction of laser- flowing always in certain direction. This is not very rapid process to be sure, but it happens. $\endgroup$ Commented Apr 16, 2015 at 4:09