Originally Posted by
planters
Simon,
I agree that what you describe sounds like an engineering flaw. This unit for all its power is still a lamp driven YAG and so it seems that the perfectly adequate single closed loop DI cooling scheme used for the 40 watt'ers should work for this as well. Allowing you to eliminate the hook up to tap water would make this a lot more portable too. If really good water quality is needed then increasing the volume and more frequent flushes should help.
I will come out of retirement for a while to help you "not so old" people.
Yes...you will need a minimum of a 4kw affinity all stainless steel chiller with closed DI recirculator (for extended operation as in a permanent installation I would recommend a 6KW) depending on the ambient air temperature of the installation.
I respectfully disagree - it is not a design flaw...it was designed as how it was intended to operate...for the most part these lasers were designed to "idle' (90% of the time) for hours prior to an operation...then a burst of current to burn that vag. If you plan to operate this cavity design for more than a few minutes (at any current over 30 amps)...you will need to increase the volume of water resivor to at least to 2 gallons of recirculating DI water (to compensate for the slow but sure rise in temperature). To remove the heat via a water to air heat exchanger you will need a minimum of a 4' x 4' area of a stainless steel heat exchanger with a minimum of 4 - 12 inch fans...or a stainless steel water to water heat exchanger capable of 2 GPM @ 40 PSI.
as said in signature...been there done that...so forth so on...
as to the other rookie mistakes he made...
The laser is Not a CW laser...yes you can run it CW....but your first failures will be the OC mirror bleaching and the secondly...the coatings on the end of the rod will start to delaminate from the outside working towards the center of rod (on a cavity based on all HR mirrors there is too much circulating power for the coatings to handle)
If he was running green and green stopped (and the lamp still operates normally) it is always a rod problem (either broken or water on ends due to o-rings leaking, which can be caused by removing the qs and misaligning the beam enough to burn the rod o-rings)
Even if KTP is BLOWN...if there is ANY available IR to meet threshold of lasing...it will emit a scattering spiderweb of some green light (a butt ugly beam, but there will be some green).
He removed the QS - not good...IR is aligned with QS installed and it basically has ZERO insertion loss
He dittolled the optics trying to find the beam...not good....(horse before cart) Now you get the experience of starting alignment from the beginning! (OBTW you better have a 2% OC alignment mirror or you are wasting your time...you will NEVER get green you want if the IR isn't there.
Photonbeam is correct - a cheap rod without the proper coatings will not yield the IR necessary to produce the specified IR prior to doubling
Same thing goes for crappy KTP - you are wasting your time with cheap KtP
I would also stop calling it a 80 watt laser until he can show 80 watts on a power meter...I don't mind him saying..." man with 18 inch dick has 80 watt laser" tho... I have a REAL problem people claiming something a laser...frankly...is not...those are called "marketing watts".
Once you have done what has been done...you will never see 80 watts out of it again until all components are brought up to "factory standards"
But I could be wrong
Pat B
laserman532 on ebay
Been there, done that, got the t-shirt & selling it in a garage sale.