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On Thu, May 26, 2011 at 5:11 PM, George Peeters
<[log in to unmask]>wrote:

> I agree that Argon gas lasers (458, 488, 514 nm lines) are by far the least
> expensive route and least costly to maintain. As mentioned , You add in
> solid state lasers for 405, 442, 561, 640 nm lines as needed. All but the
> 405 nm can be selected and controlled by an AOTF. We bypass the AOTF with
> the 405 laser and add it in prior to the FO.  Krypton-Argon mixed gas lasers
> are short lived with the red line fading early on.
>

As an aside, most of the direct-diode lasers (405, some 638, and now
520-530) can be fast power controlled via current, so an AOTF is not
required for them.


> To prolong the multi-line Argon lasers life span you do need to pay
> attention to the Current: power ratio and try to run it at as low a currrent
> as possible. Heat, room noise and size are the down side to any gas laser,
> but an Argon will last 4 to 7 years in my experience and are very
> inexpensive to retube.
>

We use ours in 'standby' mode all the time.  I think we've only ever
switched it to 'run' mode three times, for some photo-bleaching experiments!


>
> We use Dynamic Laser in Salt Lake (contact Amir Behjani <
> [log in to unmask]> )to repair all Argon and Krypton-Argon lasers that
> we run across (not only their own laser models but others as well). New
> tubes are done usually within the same week and costs are quite low.
>

Thanks for the information!  I will keep that in mind if my own Argon dies
(knock on wood!).

Craig



>
> Best regards,
> George
>
> George Peeters, M.D., M.S.
> Pres. Solamere Technology Group inc.
> 1427 Perry Ave
> Salt Lake City, UT.  84103
> office 801 322-2645
> cell    801 232-6911
>
>
>
> On May 25, 2011, at 2:24 PM, Lloyd Donaldson wrote:
>
> > Hi Yuval
> >
> > We had used Melles Griot Omnichrome Kr/Ar lasers on a Leica TCS/NT. We
> averaged 1 per year over the 14 years or so but some failed within months of
> installation. Typically the 647 line fades within 12 months. This laser is
> air cooled. A surge protected power supply is essential with batteries to
> run the fans to cool the laser if the power fails. Laser failures were
> typically at turn off with a loud bang so a bit startling for users. This
> technology is obsolete. The additional expense of solid state will be offset
> by longer service times and by the time you need to replace it the cost will
> have declined considerably. However you could consider an Ar laser - I
> understand the typical lifetime is 10,000 hours by which time a solid state
> replacement should be very affordable.
> >
> > Regards
> >
> > Dr Lloyd Donaldson
> >
> > Senior Scientist, Project Leader - Microscopy/Wood Identification
> > Scion - Next Generation Biomaterials
> > Private Bag 3020, Rotorua
> > New Zealand 3010
> >
> > Ph: 64 7 343 5581
> >
> >
> >
> >
> > -----Original Message-----
> > From: Confocal Microscopy List [mailto:[log in to unmask]]
> On Behalf Of David Baddeley
> > Sent: Wednesday, 25 May 2011 6:20 p.m.
> > To: [log in to unmask]
> > Subject: Re: which multiline gas laser should I buy
> >
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > I can't remember the exact model of Ar/Kr - it was the stock laser in a
> Leica
> > TCS NT and was air cooled. It was probably being used ~15-20 hrs/week so
> a bit
> > over 1000 hrs would be about right. We also had a couple of pure Ar and a
> pure
> > Kr large/medium frame lasers (Spectra Physics, Lexel), and these fared a
> lot
> > better although they still gave us a few headaches with tube
> replacements.
> >
> > As to tips on prolonging tube life, the commonly accepted ones are:
> > - don't run at full power - I have heard that ~20% and below is pretty
> good for
> > longevity
> > - don't switch on and off more than you have to (ie leaving the laser
> running at
> > low power all day is better than turning it on for an hour or two 2-3
> times a
> > day). Exactly where the turn on /runtime balance lies is the subject of
> much
> > debate.
> > - let laser cool properly before switching on again
> > - make sure you're cooling water setup is absolutely bombproof. Important
> things
> > to watch here are:
> >     - interruptions/ pressure variations (we think we lost a tube to a
> > water-hammer type effect)
> >     - calcification - if you've got hard water, you'll get a build up of
> > calcification in the tube - this stops it being cooled effectively, and,
> if the
> > calcification starts to flake, allows water to be trapped next to the
> tube and
> > boil (we definitely lost one tube this way). If you're stuck with hard
> water,
> > you can do a bit of preventative maintenance by rinsing the laser with a
> dilute
> > solution of a weak acid (eg. acetic) every 6 months to a year. This is
> however a
> > half solution at best as there are also metal parts in the cooling loop
> that you
> > don't want to corrode.
> >      - leaks - the required flow rates are such that any leak in the
> cooling
> > circuit will quickly flood your lab. Combined with 3 phase laser power
> supplies,
> > this is not a particularly comforting prospect.
> >
> > In general solid state lasers are much less hassle, and a lot safer. I'm
> not
> > sure what the current prices are, but would guess that either of the
> lasers you
> > are looking at would probably set you back somewhere in the vicinity of
> $50-70k.
> > You should be able to get solid state lasers at the desired powers for
> much less
> > than that ($1-5k each at your powers, if you're a bit flexible with your
> > wavelengths. If you want to exactly match the Ar/Kr lines, in particular
> 488 and
> > 514 you will need to fork out a little more). You might not be paying
> directly
> > for your power / cooling water, but gas lasers are also horribly
> inefficient -
> > the Innova 70 draws up to 25KW -> ~ $12K/year power and cooling costs
> > (calculated at 1000hrs/year, 20c/kwh[nz prices], cooling power at 1.5x
> > electrical[optimistic]). Maybe you can use this as a bargaining point to
> get
> > your institute to chip in a few extra dollars for a solid state solution.
> >
> > cheers,
> > David
> >
> >
> > ----- Original Message ----
> > From: Yuval Ebenstein <[log in to unmask]>
> > To: [log in to unmask]
> > Sent: Wed, 25 May, 2011 3:58:18 PM
> > Subject: Re: which multiline gas laser should I buy
> >
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > Hi David and Martin,
> > Thanks for your comment. I'm curios to know which Ar/Kr you were using.
> > I know at least two Coherent heads that are running on the same tube for
> several
> > thousands of hours and for over 10 years.
> > I totally would prefer solid state but I need 4-5 lines with high power
> > (150-250mw) and the solid state at these intensities are super expensive.
> > Overall I will be paying about double for a solid state set and I just
> can't
> > afford it.
> > Would love to hear more and get tips for extending their life...
> > Yuval
> >
> > On 5/24/2011 8:21 PM, Martin Wessendorf wrote:
> >> Deare Yuval--
> >>
> >> I second David Baddeley's comments.  Kr/Ar's were a great idea at the
> time
> >> (1993) but are obsolete for exactly the reason he mentioned: they tend
> to die
> >> young.  We always figured on 1000 hours out of ours.
> >>
> >> Good luck!
> >>
> >> Martin
> >>
> >> On 5/24/2011 7:28 PM, Yuval Ebenstein wrote:
> >>> *****
> >>> To join, leave or search the confocal microscopy listserv, go to:
> >>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> >>> *****
> >>>
> >>> Hello,
> >>> I'm looking for a cheaper alternative for a high power solid-state
> laser
> >>> combiner.
> >>> I'm thinking of buying an Ar/Kr (which gives almost every excitation
> >>> line I can think of) and I can't decide between the Innova 70c-spectrum
> >>> from Coherent and the Stabilite 2018-RM from Spectra-physics. They are
> >>> quite similar on paper but the spectra one is cheaper. I heard much
> >>> about the robustness of the Coherent model.
> >>> Anyone has experience with one of these? Anything special I should look
> >>> for?
> >>> Many thanks
> >>> Yuval
> >>>
> >>
> >>
> >>
> >
> > -- --------------------------------------
> > Yuval Ebenstein
> > Department of Chemistry and Biochemistry, UCLA
> > Young Hall-2002, 607 Charles E. Young Drive East
> > Los Angeles, CA 90095-1569
> > Ph: (310) 794-6685; Fax: (310) 267-4672
> >
> >
> >
> >
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