Is this normal behavior for a green laser?

[Kdog701]

Long time since I was last on here, got caught up in knife collecting/designing.

Anyways, I recently sent my 500mW 532nm Jetlasers Equality series back to have a repair done because it was only outputting ~10-50mW on fresh batteries. Anyways, I haven't gotten it back yet but I asked Gray to power test it for me and he sent me a 2-minute video of the output. I can't figure out how to show that video here so in order to show all of you and because I have way too much time on my hands right now I drew this graph of the output. I labeled the power every 5 seconds with all local minimums and maximums labeled to the second.



A 610mW peak with average over 500mW is fine with me, I'm just wondering if the fluctuation from the low 400s to 600 is normal for a green laser. I know it is expected that it will reach a peak and level off, but I've never seen that much ocsillation before or two consecutive peaks of high power. Could that be from it switching in and out of TEM00?

And if you really want to see it for yourself, I have the video as a .mp4 file on my desktop, I just need to know how to get it on here.

Thanks.

 

[Dr_Evil]

A DPSS laser will fluctuate. Especially if it's used in a cool to cold environment.

 

[diachi]

A DPSS laser will fluctuate. Especially if it's used in a cool to cold environment.

Or a rather hot one...

 

[Deleted member 16589]

Or a rather hot one...

er or any temperature if its not Temperature Stabilized. :tinfoil:

 

[Kdog701]

Yeah I know DPSS will do that, just thought this was more than usual. My next high-power green laser is definitely going to be a 520nm so I don't have to deal with this.

 

[Crazlaser]

Yeah I know DPSS will do that, just thought this was more than usual. My next high-power green laser is definitely going to be a 520nm so I don't have to deal with this.

520 does have the benefit of diode stability but when it comes to color, nothing beats 532 in my book.

 

[dden4012]

Yeah I know DPSS will do that, just thought this was more than usual. My next high-power green laser is definitely going to be a 520nm so I don't have to deal with this.

Trade a dot for a bar and some splash. I have been looking at a few high end 532nm but I'm so ocd about alignment and centering I don't know if I could drop $800 on almost perfect dpss. And the other stability issues that go with high power 532nm. The scale of the parts involved makes perfection impossible. If the beams aligned with the host then its off center. If its centered then its out of alignment with the host. I just can't deal with that. I would rather deal with direct diodes. I don't know why the high end 532nm handhelds do not have a correction assembly like a pistol pictany laser. 4 screws to center and align the heatsink module.

 

[Benm]

The fluctuations you see are fairly typical, normal behaviour, for a DPSS.

They are caused by relative temperatures in the pump diodes, solid state laser and doubling crystal. Depending on the temperature of each of these the wavelengths match better or worse and the doubling efficiency also varies.

If the host is capable of continous operation you should see it stabilize in a constant temperature room after several minutes, perhaps even an hour for everything to heat through and become balanced out.

It is possible to compensate for this by controlling the temperature of each component individually in larger professional systems, but this is not that practical in portable lasers. Apart from needing space and power for the temperature control, the solid state laser and doubler crystal will probably be one assembly with no means of controlling their temperatures individually.