532nm green normal function or not?

[whiteg]

My laserwave green 532nm module light ad stripe line. Not uniformly distributed.
Is this module fault, or the normal work than DPSS laser?
The red and blue diode module is ad nice lines.

[infredible]

If this scanned then I suspect dirt on one of the scanner mirror.

Fred.

[whiteg]

No, the scanner mirror is clean, work perfectly.
Only green light striped.

If this scanned then I suspect dirt on one of the scanner mirror.

Fred.

[ams09]

Hi Whiteg,
Can be a thermal instability. Is a module to one or two TEC? In both cases it will try to raise or lower the temperature of the crystals, measuring in at full power (after a heating time of ten minutes just above the threshold current).
Regards.

[whiteg]

Ok, Thank you the information.

Hi Whiteg,
Can be a thermal instability. Is a module to one or two TEC? In both cases it will try to raise or lower the temperature of the crystals, measuring in at full power (after a heating time of ten minutes just above the threshold current).
Regards.

[norty303]

I think what you're seeing there is classic jellybeaning effect.

[whiteg]

What is the jellybeaning effect ?

I checked the module after power on 1 minute and after 30 minute and the green light striped, not changed.


my module simple horizontal (vertical also) line light is similar than the photo: http://image.dhgate.com/albu_3194888...laser-show.jpg

[norty303]

Search the forum for jellybeaning discussions.

[edison]

Hello Whiteg

Although its a dpss blue, its virtually the same....

Here is the explanation from a REAL expert copied from another thread :

Jelly beaning is basically noise in the beam If you were to see an oscilloscope representation of the output it would resemble white noise. Its caused by instability in the laser usually (but not exclusively) due to temperature. The problem with blue is to get the best power you need to be very specific with temp of internal parts. This is ok in CW mode as its predicatable but when you start modulating the stability goes out the window and the Tecs cant keep up with whats going on and can never know whats coming next. Part of the problem I believe is due to most modules having single ended tec control - which means the tec can only heat OR cool the internal parts not both. To get very accurate and stable temp even when modulationg takes a few tricks in the driver but the fundamental thing would be a tec control that can heat AND cool the xtals/diode

Rob

http://www.photonlexicon.com/forums/...y-beaning-blue

[whiteg]

Ok and thank you.
I learned something again.

Hello Whiteg

Although its a dpss blue, its virtually the same....

Here is the explanation from a REAL expert copied from another thread :

Jelly beaning is basically noise in the beam If you were to see an oscilloscope representation of the output it would resemble white noise. Its caused by instability in the laser usually (but not exclusively) due to temperature. The problem with blue is to get the best power you need to be very specific with temp of internal parts. This is ok in CW mode as its predicatable but when you start modulating the stability goes out the window and the Tecs cant keep up with whats going on and can never know whats coming next. Part of the problem I believe is due to most modules having single ended tec control - which means the tec can only heat OR cool the internal parts not both. To get very accurate and stable temp even when modulationg takes a few tricks in the driver but the fundamental thing would be a tec control that can heat AND cool the xtals/diode

Rob

http://www.photonlexicon.com/forums/...y-beaning-blue