Newbie question regarding o-like laser

[opr]

Hi all.

I am a newbie and first I want to thank this forum for all the interesting posts I read here.

After reading all kind of recommendation, I ordered a 200mw Green laser from O-Like. The main purpose of this laser is as an astronomy pointer.
The main issue I face is that after 2 minutes (more or less) of constant usage, the power decrease significantly. It is very disappointing. This contradicts this I read in this forum which says that a Green laser supposed to increase as it warms.

I checked, and it is not a battery issue.

I contacted O-Like, and Susie wrote they will replace it.
But before I do all the long process of sending it and wait for a new one, I would like to ask if any other people faced the same problem. I’ll hate to get a new one, and see that it is a general problem.

What the expert’s opinion?

 

[RA_pierce]

What do you mean when you say you use it for astronomy?

Do you use it to point out objects? Mounted to a telescope as a guide?

As a pointer, 200mW is pretty bright. I like 30-50mW for a pointer.
As a guide on a telescope I used to use a 200mW green. It was great, but green is not the most stable. I am planning on making a new guide with a 125mW 450nm or 635nm. Or a green diode if they ever are released.

450nm and 635nm will not be as bright but they are diode lasers which are much more stable in a wider range of temperatures and are easy and inexpensive to DIY.
Also, 635nm is a red wavelength and so it does not have as much of an effect on night vision. However, if you want to use a diode laser for a telescope guide, make sure it is a single mode diode. Multimode diodes have rectangular beams and high divergence which is not ideal for long distance pointing.


About your laser's problem...
It could be a problem with temperature. If the laser overheats during use it may drop power and/or mode shift.
It could also be a battery issue. Try new batteries.

If there is anything at O-like that is a comparable value and may be better suited for your needs, maybe you can see if Susie will exchange it.

Hope this helps

 

[opr]

Thanks for your answer, RA_pierce.
I tried fresh charged batteries, and it is the same.
I believe it is related to some kind of warming of the laser.
The main question: Is it normal for such laser to reduce the power in time? Or is it a faulty laser?

 

[Clay Westin]

Does your laser have a duty cycle? For example 60 seconds on 30 seconds off?

 

[opr]

I don’t really know.
In the laser page there is no such thing.

(Power Rock Green laser Torch 200mW /Focusable&Waterproof [OLPRGL200] - $132.99 : Zen Cart!, The Art of E-commerce)

And in fact this is the reason I choose o-like. Since I thought there is no Duty Cycle.
But after more research, I learn that other 200mw laser almost always have a duty cycle (For example Lazerer).
Do you think this is the problem?
If so, why Susie from o-like offered to replace it?
Very confusing.

 

[opr]

Some news.

Susie just wrote me as follow:

Hello
Sure we test output power and make sure it is in specification
But our laser has duty cycle ,you'd better light it 20 seconds on and then 3 minutes off

If so, it is a completly useless laser.

 

[Eudaimonium]

You should follow the duty cycle, but not as strict as she made it seem.

1 minute on and 20-30 seconds off should be pretty good for 200mW module in that host.

Take note, that you are not obligated to run it exactly one minute.

You can run it as long as you want, with a maximum of 1 minute on time, with off time scaled accordingly or well, personal preference.

Duty cycles are never really as strict as sellers make them seem, it's in their best interest to not have the customers breaking lasers about and asking for refunds.

2 minute on for 200mW module to accumulate enough heat to start dropping power sounds perfectly normal.

 

[opr]

Hi Eudaimonium
Thanks for your answer.

If I understand you correctly, you say that It is a normal behaviour for a 200mw laser to reduce its power while it warms.

Is it some kind of protection?

Does yours act the same?

 

[Eudaimonium]

Yes it's normal,

It's actually the driver (current regulation electronics) that heat up a lot, module itself with all the optics is fine.

When components like current regulators heat up, they decrease the current to prevent burning out, hence weaker laser.

You mentioned that green lasers increase in power when warmed up, that's only partially true. When green laser setup is below it's operational temperature range, it will drop in power or develop weird operating modes, but if it's within the range, it's good. If it gets heated up above the range again, power goes down.

 

[LarryDFW]

Eudaimonium is correct.

The IR pump diode is sensitive to temperature.

Some will work poorly when cold (most common).

Some will work poorly when too hot.

Try operating in a very cool area and see if works longer.

LarryDFW