continuous duty, diode vs DPSS from laserlands

[runcyclexcski]

Hi all again,

This is a follow-up of my post 2 days ago on a continuous duty (16 hrs non-stop) 1 W+ 532 for lab work. I got some good suggestions from folks here, and I am considering buying from laserlands.

I wonder if folks here have experience with their 200+ mW DPSS and 'dot' modules (2x price difference). Their 1-2 mrad pointing stability is OK for me so is the power stability of 5%. But do they last their projected 5000 and 10,000 hrs? Has anyone sent their units back to laserlands for repair (they do not seem to offer warranty -- dodgy)?

I am now thinking of getting five 200 mW units instead of one 1 W, as the scaling of prices is almost linear. In my application I have to bleach 5 pieces of glass, so I figured I would dedicate one unit per glass (unless one can recommend very cheap 50/50 beam splitters -- cheap means under $20 ). Plus, if I split 1W into 5, I would lose everything if the single unit goes down, but I can still sustain the operation if one out of 5 goes down.

Cheers!

 

[Benm]

These figures are hard to interpret. A so-many thousands hours of life doesnt mean very much unless you mention what the condition of failure is.

For things like LED lights 'failure' is often considered at the point where output light is 50% of specified or less. With laser devices it is rarely mentioned what the criterium actually is.

Lets say you got a 200 mW 532 dpss module, and after 5000 hours the green output is still there, but only at 10 mW. Would that be a fail because it is so low, or a pass because it 'still works' to some degree?

And a scenario of output power dropping rapidly with pump diode degradation isn't that crazy either. Due to non-linear action in the doubling crystal, a decline of pump light of 50% could cause a green output loss of 90 or even 99%. It would still work as a dpss laser at that point, but i'd consider it failed.

If someone promises a lifetime for a product, always ask what is still considered 'alive'. Otherwise someone could easily state a million hours for a laser, outputting only 0.01% of it's specced power at that point

 

[runcyclexcski]

Hey, that is a great point regarding the non-linearity of the pump. Good to know. :thinking: I am a biologist by training, you see

I hope they can answer the lifetime question, rather than ignoring my request and moving on to thousands waiting to get their cool laser pens But I usually find Chinese engineers quite responsive.

Regarding LEDs, I have some Roightner 2W 850 nm ones that were on for 4+ years essentially non-stop. The only time one died is when a student fried it with 10V hoping to get "more light" out of it. The chip actually turned black, I use it as a bad example.