I know that when power drops below a certain threshold you experiance mod-hopping, however, I was wondering which causes the mode hopping; the diode or the crystal, and what's acctualyl going on when it's mode hopping? are parts of the crystal/chip the lasing proerly or...?
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What is mode-hopping - Chrystal or Diode?
- Thread starter Ashton
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you mean mode changing between TEM modes? That is because of the crystal. Inside the cavity, the profile has to be the same after it makes a complete pass back and forth between the mirrors. The fundamental profile for that behavior is TEM00, but different stresses on the crystal, aperture, etc. can force other TEM modes.
Mode hopping (longitudinal modes as opposed to transverse [TEM=Transverse Electromagnetic Mode]) is with the diode as temperature changes
Mode hopping (longitudinal modes as opposed to transverse [TEM=Transverse Electromagnetic Mode]) is with the diode as temperature changes
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SenKat
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Pseudo - exellent explaination. I think some folks have lost sight of exactly how lasers function -
The energy bounces back and forth between two mirrors until it reaches enough energy to go out of it's little home, and lase for all of us to enjoy
Kinda like digi-Pong on speed !
The energy bounces back and forth between two mirrors until it reaches enough energy to go out of it's little home, and lase for all of us to enjoy
Kinda like digi-Pong on speed !lol. I didn't know exactly how it worked, but I knew that little mirrored 'bowl' was vital (somone acctually told me that when a LD burns up you could (in theory, not in application, waaaaaay too expensive to really do) you could go in there and repair the reaction chamber and the LD would work perfectly again!
Thank you, pseudo, that's exactly what I was wanting to know! I appreciate the info, both of you!
Thank you, pseudo, that's exactly what I was wanting to know! I appreciate the info, both of you!
usually when you "blow" a diode ( in my definiton a blown diode is dead ) you cook the junctions, where the electrical connections are.. you can however also cause catastrophic optical damge, like when you make a LED, and that is because you got the power so high it melted the facet or lense on the diode where the light is emitted.. that's not really fixable either. if you just cook the junction you might be able to resolder the diode and make it work again but i doubt it.
as far as dpss, usually you blow the diodes before the crystal , but if you overdrive a crystal enough, you can cook it too. that starts looking like a line or gray barbar in the crystal. you can also split hybrid crystals or do lots of other things to them. you usually see this kind of thing in stuff that's not sized for the application.
as far as dpss, usually you blow the diodes before the crystal , but if you overdrive a crystal enough, you can cook it too. that starts looking like a line or gray barbar in the crystal. you can also split hybrid crystals or do lots of other things to them. you usually see this kind of thing in stuff that's not sized for the application.
