Another one viasho is dying in front of my eyes

[Frank]

Hi,Bbe

Well, if you are sure that you can readjust the driver after you get the laser head again,then it is OK to send only the laser head back.

Frank

Hi Christophe,

Another big problem of design - hugely primitive optics mounts. I was very surprised when I saw them for the first time. Many people will argue - if you need a good laser - buy jenoptik or something like that. I can agree only partially - Viasho positioned itself as a professional company, it is abnormal when a commercial product works only 100 hours of 10,000 hours, regardless of what technologies (crystals or mechanics) is used in these products. It is my opinion.
As for temperature stabilization - I did some tests on this point. Temperature measured on a baseplate in the vicinity of the ndyvo4 crystal at various diode currents:

0,5A...23,9C...0mW
1,5A...24,1C...5mW
2,5A...24,2C...70mW
3,0A...24,5C...90mW
3,5A...24,8C...140mW
4,0A...24,8C...410mW
4,5A...24,9C...400mW
5,0A...25,0C...440mW
5,5A...25,0C...570mW
5,8A...24,9C...630mW

It is obvious that the optic power does increase non-linearly, but the temperature of the baseplate is quite stable. What do you think about this?

As you can see, Frank replied here (maybe it's a coincidence or magic power of this forum). He offers to ship the module and driver back to China, but I am inclined to send the module without driver, because I believe that it is a waste of money.

Let's see what will happen next....

[ams09]

Hi Bbe,

It is not on the base plate to do temperature measurements, but closer to the crystals, and we see that there are big differences of more than 20 ° C, and small aluminum frames thermal stress should influence the mechanical stresses, hence the almost systematic misalignment of this type of head.
Other manufacturers have all chosen frames copper or tin plated brass for crystals and independent temperature control, this may not be for nothing.

Regarding the proposal to Frank for the realignment of the head alone, it is doable, but you have all the settings on your resume a driver for it to work properly.

It is very a pity to make lasers with very good beam characteristics, but they only last for the time of the trip ...

Cheers, Christophe.

[Bbe]

I did some tests for "viasho" style crystal mounts

Input data:
Pump power 5W
Crystal efficiency 50%
Baseplate temp - 25C

For aluminium - 26.7C (the edges of the crystal)


For copper - 25.75C (the edges of the crystal)


As we can see- difference exists, but it is not dramatic difference

It is not on the base plate to do temperature measurements, but closer to the crystals, and we see that there are big differences of more than 20 ° C, and small aluminum frames thermal stress should influence the mechanical stresses, hence the almost systematic misalignment of this type of head.

I do not expect to get nano-space characteristics with this module, ha-ha

It is very a pity to make lasers with very good beam characteristics, but they only last for the time of the trip ...