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Date sent: Mon, 4 Apr 2005 15:47:44 -0700
From: Danielle Crippen <dcrippen@BUCKINSTITUTE.ORG>
Subject: Re: SUMMARY Ti:sapphire Spectrum Physics or Coherent
A thousand thanks to all whom responded to my
question. I've compiled a summary
below for anyone also interested in this topic.
Cheers,
Danielle Crippen
Morphology and Imaging Core Manager
Buck Institute for Age Research
8001 Redwood Blvd.
Novato, CA 94945
415-209-2046
dcrippen@buckinstitute.org
We just got the 510 with the Coherent Chameleon
laser. It is software
tunable from within the 510 software and mode
locks automatically. A
huge difference from either the MaiTai or the
MiraVerdi. I don't know
if SpectraPhysics offers a comparable laser.
Kate Luby-Phelps, Ph.D.
Director, Live Cell Imaging Core Facility
Associate Professor, Dept. of Cell Biology
UT Southwestern Medical Center
5323 Harry Hines Blvd.
Dallas, TX 75390-9039
We've had outstanding support for our Spectra-
Physics Tsunami, and the
system has been very reliable; I feel that the
service/support is a
major factor, and unfortunately, this can vary from
region to region.
Some basic reliability/performance factors that may
enter in to the
decision making process are tunable range, pointing
stability, pulse
repetition rate, the pump laser technology,
pulsewidth/spectral
bandwidth, average power output, provisions for
future upgrades etc.
Contrary to much of the confocal industry, the laser
companies will
provide meaningful performance specifications for a
wide variety of
parameters in the context of thier products. Both
the Mai Tai and the
Chameleon will work well in the context of the 510
software interface
and optical train.
The differences between the Mai Tai and
Chameleon are subtle; the
things I would be most aware of would be the
pointing stability w/
regard to tuning to different center wavelengths,
what the max av. power
vs. wavelength curve looks like, how long the pump
diodes are supposed
to last and what sort of Warranty or service contract
costs may be
associated with the lasers. The pump laser stability
and service life
before diode replacment is an issue to consider as it
will likely be a
cost of ownership issue that needs to be planned
for. If there are other
research institutions in your area housing ultrafast
lasers, you may
find out what thier experiences have been.
Part of the system-wide stability can be
influenced by factors
outside the laser head; for instance, an ultrafast
broadband isolator
can be used to prevent reflected pulses from re-
entering the laser head
and disrupting mode-lock. The cooling
system/ambient temp. need to be
stable for best performance. Direct coupling
alignment needs to be done
carefully. Problems with the pump diodes can
negatively impact the
stability of the Ti:Sapphire output too.
Regards,
Karl
We purchased a Zeiss 510 NLO about one year ago. The laser we got is the Coherent Chameleon, rated from 720 nm to 930 nm.
After some initial problems that were quickly fixed by the Coherent engineers, the laser has been working beautifully. Laser control is done entirely through the Zeiss software. At start- up, the laser takes a minute or two to warm-up and lock to the set wavelength. After that, it typically takes in the order of about 30 seconds or less to tune to a new wavelength. It has been recommended to us to change wavelengths by small increments (up to 30-40 nm at a time) to reduce the risk of losing mode-locking, but we have occasionally tried longer "jumps" without problems. Once it is mode-locked, the laser is stable and does not (generally) lose mode-locking. The Chameleon has a closed-loop chiller to maintain cavity temperature, and a filtered air recirculator to deplete moisture. Coherent claim this allows tuning at the long wavelength end of the spectrum (Water absorbs in that range). We rarely work at the long wavelength end of the spectrum, but I did not notice any problems.
Zeiss provides a macro that can automatically"scan" through the range of wavelengths (for excitation fingerprinting). We have never bothered using it, as it is pretty straightforward to do the same manually, but it can be done. The Chameleon is very easy to use: turn the key on the power supply from "Standby" to "ON", activate the laser on the LSM software, and set the wavelength. From then on, it is used just as another laser line.
The peak power of our Chameleon is about 1.3-1.4 Watts at 800 nm, and there is still sufficient power at the ends of the tuning curve for most needs (about 0.5-0.7 Watts).
In summary, we found the Chameleon to be robust, low-maintenance, and easy to use. The new Chameleon XR should be even better, as it has an extended tuning range from 705 nm to 980 nm (and somewhat higher power throughout). This should provide even better excitation of many fluorescent molecules (e.g. NADH at 705 nm, and YFP at >900 nm)
Hope this helps...
Julio.
I've only worked with the Spectra-Physics (Tsunami and MaiTai) but I've worked with them on both coasts with very different results.
On the west coast, the lasers (Tsunami and MaiTai) were very stable and very easy to use. I'm not sure what you mean by"robustness." On the east coast, our Tsunami is still easy to use, but in terms of stability, it is a very different story. To be more specific, maintaining mode-lock through a range of 700nm-950nm is difficult at best. Above 950nm the system is nitrogen purged as well (something we didn't need to do out west, San Diego). I believe this is probably related to climate ((humidity) above 950nm). Both rooms also were closely temperature controlled as well.
We've had the Tsunami serviced here and it is still the same.
Best,
Gary
we are very much a multi-user facility (730 users last year from 258 account holders and 68 departments and groups)we have a Spectra Physics MaiTai TiSapphire laser on a Bio-Rad for three years. It has been on service contract from the beginning and it died in the first year while still under warranty. Apart from the period when it was changed it has been very reliable and extremely easy to use. No aligning and mode locking necessary. The newer models I understand are even better with a wider range. The training time on the MaiTai is maybe one minute while the tuneable TiSapphires take a lot longer.
Elaine
I read your post on the confocal list, and take the liberty to answer you directly. I would like to draw your attention to a new type of femtosecond laser, that answers very well your needs for ease of use, robustness and stability.
Amplitude Systemes manufactures diode-pumped femtosecond lasers usingv Ytterbium as the active material. Ytterbium doped lasers can be directly diode-pumped with high reliability laser diodes, and do not require the intermediate green pump laser used in Ti:Sapphire lasers. The laser is therefore extremely reliable and easy to use (simpler system, low consumption, no servos or sophisticated feedback required).
The t-Pulse femtosecond laser features high optical performances:
Average Power: 1W Repetition rate: 50 MHz Energy per pulse: 20 nJ Wavelength: 1030 nm Beam quality: TEMoo
The laser has a small footprint 60x20cm (< 24x8 in), features hands-free operation and low cost.
The laser has been proven to work well with most commonly used fluorophores. It is comparable to Ti:Sapphire on GFP, and much more efficient on red fluorophores.
The t-Pulse laser is a direct drop-in replacement for setups currently using Titanium Sapphire lasers. Because of the small footprint of the system, it will easily fit in the space allocated to a Ti:Sapphire laser. Its wavelength is close enough to the highest wavelength reached with Ti:Sapphire laser so that no specific optics has to be changed into the microscope.
Integration of the t-Pulse laser has been tested on many commercial and home made microscopes and is very easy.
Additional information on the company and its products is available at www.amplitude-systemes.com.
You will find attached a small flyer on the laser and its application to multiphoton microscopy. Let me know if I can be of any further help.
With best regards,
Eric
Eric Mottay President - CEO
Amplitude Systèmes Parc Scientifique Unitec 2 351 Cours de la Libération 33400 Talence - France Tel 33 5 4000 3447 - Fax 33 5 4000 3444 Email emottay@amplitude-systemes.com Internet www.amplitude-systemes.com
We went through the same procedure about a half a year ago. Finally we had chosen the Chameleon - mainly because it was said that the collaboration/communication between Zeiss and Coherent (in Switzerland) is somehow better. This turned to be false.... Parameter wise (as others have also mentioned it ) the Mai Tai and the Chameleon are identical and also on the Zeiss-software control side there is no difference. So I'd suggest that you take the cheaper one (in our case this would have been the Mai Tai).
Gabor
