Hi all,
thanks for the suggestions: after checking/setting chiller/baseplate
temperatures our Chameleon laser
again is stable as usual.
Actually Chameleon manual states that proper temperature settings are
important, and now based on my own experience
I can confirm that they are REALLY important. Fortunately the laser
performance has nothing
to do with crystal degradation as follows from the replies and my enquiries
to Ti:Sa laser owners.
Arvydas
>>> "G. Esteban Fernandez" <[log in to unmask]> 11/13/2008 12:56
PM >>>
We had modelock problems for some time but the laser has been very reliable
(or at least predictable) since we've been setting the chiller temp. to 27*C
at start-up. This is higher than the what the laser should be operating at
and may give a diode overcurrent fault, so we only use that temp. for
start-up. Once it modelocks we turn the chiller back down to 23*C. Of
course it doesn't like the temp. change but it seems less harsh than
smashing it with your hand :) Contact me off-list for the dirty details of
how we keep modelock without having to spend $40k.
-Esteban
On Wed, Nov 12, 2008 at 12:37 PM, LANCE RODENKIRCH
<[log in to unmask]> wrote:
Hi Arvydas,
I would check my baseplate temperature. Main menu/Pump laser menu/verdi
laser status/baseplate temp. The baseplate should be 33 C. Are you using
the original Thermotek pump that was shipped with the unit?
Coherent advises to change the chiller water monthly. Can you achieve
modelock by doing a pzt recovery? Main menu/chameleon status/PZT recovery.
If this is a temperature problem, you should get error codes number 44 and
50 on the front interface. I have 6K hours on a 5 year old Chameleon but I
have been having similar issues since July. To other Chameleon operators
out there, how often are they doing PZT recoveries?
It would be best to start the laser at a known calibration point such as
800nm and then tune to the desired wavelength. A standard Chameleon has
23 calibrated points across the tuning range.
The system will first attempt to modelock at the desired wavelength.
Should it not modelock on the first try, it will tune to the next
closest calibrated point, modelock, then tune back to the desired
wavelength so that a modelock pulse is obtained.
Lance Rodenkirch
W.M Keck Laboratory for Biological Imaging
University of Wisconsin School of Medicine
1300 University Ave Rm 172 MSC
Madison, WI 53706
http://www.keck.bioimaging.wisc.edu/
Phone: 608.265.5651
Fax: 608.265.5536
----- Original Message -----
From: Arvydas Matiukas <[log in to unmask]>
Date: Tuesday, November 11, 2008 5:12 pm
Subject: Coherent Chameleon laser lifetime
To: [log in to unmask]
> Our Coherent Chameleon laser which was ocassionally
> used for 2p or 2p-DAPI excitation on LSM510 system
> recently began performing unstably, sometimes even
> not getting "modelocked".
>
> The laser is 4 years old but was used only 1000 hrs.
> However, Coherent engineer states that lasing crystals
> may have degraded and suggest to replace them for $15-30k
> with one more year warranty.
>
> I would appreciate any advice/comment on cheaper options
> and laser lifetime.
>
> Thanks,
> Arvydas
> *************
>
>
>
>
> Arvydas Matiukas, Ph.D.
> Director of Confocal&Two-Photon Imaging Core Facility
> Department of Pharmacology
> SUNY Upstate Medical University
> 766 Irving Ave., WH 3159
> Syracuse, NY 13210
> tel.: 315-464-7997
> fax: 315-464-8014
> email: [log in to unmask]
>
--
G. Esteban Fernandez, Ph.D.
Associate Director
Molecular Cytology Core Facility
University of Missouri
120 Bond Life Sciences Center
Columbia, MO 65211
http://www.biotech.missouri.edu/mcc/
573-882-4895
573-884-9395 fax
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