Advice with old chameleon laser.

[laserchs]

New to this forum, so please forgive me if I am posting in the wrong place. I am trying purchase an old coherent chameleon laser (~14 years old) with about 3500 hours of usage on both diodes and laser head. I am trying see what issues I need to be aware of with this old laser system. We will mainly be using this as light source of some 2P imaging. Thanks in advance.

[mixedgas]

How many hours on the pump diodes?

Steve

[laserchs]

It has about 3500 hrs on both diodes (Verdi 18W)

[kecked]

It has about 3500 hrs on both diodes (Verdi 18W)

so essentially they should be dead or about 50% power. Well those diodes are serialized, need changed by coherent, and cost 5-10k each if you can find them. You can defeat the serial but it’s not easy.

that laser sounds like it’s time for the long sleep. Unless you must have that laser or get it for like 1k walk away.

you can buy a laser for two photon for under 5k. Just get a qswitched two trees 1064nm. Does 15kw 2-3ns 2 w average, and cost 500.00. It’s pwm controlled and you can even do single pulses. I assume your scanning? Unless you are using STM. Damn expensive but I’m looking into that myself. Structured light modulators phase only can replace the whole need for scanning. The camera is also rather expensive. Rest is just optics and filters.

depending on what you want to image, the input power and pulse length matters so you don’t destroy the sample. 2ns is pretty long. A qswitched and or modelocked Ti:Saph is a better choice. Plus more dyes to select if you need them for protein work. I am doing metals so it doesn’t matter. You can find a used tisaph and drive it with a 5W green. I’ve even used diodes. I pumped with 445nm and it worked….CW. For mode lock well you need something stable to lock too so then a verdi 80mhz is called for.

so saying 2p isn’t very helpful. That laser is tired.

[laserchs]

Thank you so much. WeÂ’ll be scanning. Curios to know, what is the general lifetime of these diodes? As in after how many hours of usage do these start to die. We are on a budget so, IÂ’ll look into the q-switched system but I am afraid imaging some of the brain regions with nanosecond laser might be a bit tricky.

[kecked]

Thank you so much. WeÂ’ll be scanning. Curios to know, what is the general lifetime of these diodes? As in after how many hours of usage do these start to die. We are on a budget so, IÂ’ll look into the q-switched system but I am afraid imaging some of the brain regions with nanosecond laser might be a bit tricky.

likely the ns laser would put to much energy in the tissue. About 10-15k hours maybe but at reduced power. You don’t need a whole lot of power power if you got short pulses with high peak.

[mixedgas]

Slightly different take on the pump diode issue.
For what your doing you may need less pump.
Have the current owner plot diode current vs green output and send the plot to Coherent Service. See what they say.

At my present employer we get really worried at 3500 hours, but have had diode sets make it to 7000 hours.

I agree with Kecked, I'm weary of pump diodes.


if your dead set on the Chameleon, you might want to take a look at a Sprout, for a pump, from Lighthouse Photonics.
Lighthouse's founding engineer designed Verdi.


My former employer's chief service engineer loved the Sprout product as reliable and cost effective.

Steve

[laserchs]

Thank you, both. I will look into the sprout pump as well (is it easy to replace the Verdi with the sprout 18W pump?). My hope is that this chameleon system lasts for atleast 2 years, by then we'll hopefully be able to get a newer system. The current output at 800nm for this system is ~3W, which I think should be more than enough for what we want to do. So just trying to make sure if this older system and diode hours will last for that 2 year timeframe.

[kecked]

Thank you, both. I will look into the sprout pump as well (is it easy to replace the Verdi with the sprout 18W pump?). My hope is that this chameleon system lasts for atleast 2 years, by then we'll hopefully be able to get a newer system. The current output at 800nm for this system is ~3W, which I think should be more than enough for what we want to do. So just trying to make sure if this older system and diode hours will last for that 2 year timeframe.

thats 17500 hours. Normally we leave the systems running in idle.

[mixedgas]

When you get the system, carefully follow the manufacturer s
guidelines on the cooling water.

More lab lasers die of Corrosion then anything else.

Avoid the temptation of using DI/RO water unless the manufacturer calls for it. I've machined/rebuilt replacement Verdi external cooling plates a few times over the years.
Crud and Algea tend to find their way to diode pump blocks, as they are the warmest spots.

Don't just refill, clean the system and flush it every six months. I prefer Citranox for cooling loop cleaning, in very tiny amounts, with any resin cartridges removed or bypassed.

Lasers on closed loop cooling live far longer. Especially if the correct Corrosion Inhibiter is used, if needed.

Make sure you tie the cooling systems interlock output to the pump laser interlock input. This may require the intervention of a good laboratory technician with electronics skills.

Steve