Re: which multiline gas laser should I buy

Posted by Craig Brideau on
URL: http://confocal-microscopy-list.275.s1.nabble.com/which-multiline-gas-laser-should-I-buy-tp6401184p6404940.html

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We have a Melles Griot Argon Ion emitting 457, 476, 488 and 514.  It is
backed up with a 405 and 638 diode laser and a 561 diode-pumped solid state.
 Right now your best bet is probably a combination of a regular Argon:Ion
and any diode lines to cover what the Argon can't provide.  By the time the
Argon dies (should last for years) then diode lasers should be much cheaper.

Craig


On Wed, May 25, 2011 at 2:24 PM, Lloyd Donaldson <
[hidden email]> 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 technology is obsolete.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:[hidden email]]
> On Behalf Of David Baddeley
> Sent: Wednesday, 25 May 2011 6:20 p.m.
> To: [hidden email]
> Subject: Re: which multiline gas laser should I buy
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
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>
> 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 <[hidden email]>
> To: [hidden email]
> 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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