Spectra-Physics Tsunami - Converting between Overlapping Optics Sets

Alignment
6-33
Converting Between Overlapping Optics Sets
The following procedure is applicable only when converting from ps to ps
or from fs to fs-only.
With the exception of pump mirror P
1
and the GTI (ps configuration only),
all mirrors are captured and held in place by a screw-in holder. Unscrew the
holder and the mirror will come out with it. The optic is retained by a small
o-ring and is removed by simply grabbing the exposed barrel of the optic
and pulling it straight out of the holder.
Each optic has a v-shaped arrow on its barrel along with its part number.
The arrow points to the coated surface that faces the intracavity beam. If
you need to verify the location of the optic in the laser, refer to the tables
located at the end of Chapter 10, “Options and Accessories.”
Unless you are certain the new optics are clean, clean each one as it is
placed in the laser. Refer to Chapter 9, “Maintenance,” for information on
cleaning optics.
To change between overlapping wavelength ranges, follow the same proce-
dure outlined under “Converting Between Non-overlapping Optics Sets”
above. However, note the following:
1. Before making the conversion, tune the laser to a region overlapped by
the two optic sets, and optimize laser output. Refer to the tuning curves
in Chapter 3.
2. During each adjustment following the installation of an optic, instead
of only verifying that the cross-shaped fluorescent image is visible on
the white card, adjust the optic to get the system lasing. Once lasing,
adjust only that optic for optimum output at that wavelength. Do this
for all optics except mirror M
3
. Mirror M
3
is changed last.
3. When M
3
is replaced, place a white card in front of M
5
, and adjust P
2
to
overlap the two fluorescent ovals so they form a cross-shaped image.
4. Remove the white card and adjust P
2
until the system lases and output
power is optimized.
This procedure requires you to replace optics while using the laser at
high power. For safety, close the pump laser shutter every time you
change an optic, and only open it during alignment. Protect yourself
with appropriate eyewear at all times.
Danger!
Laser Radiation
Always use clean finger cots or powderless gloves when handling
optics.
Caution!
Verify the Tsunami meets specified power for the installed optic set
before changing optic sets. Refer to Chapter 7, “Operation: System
Start-up,” and to the specifications listed in the tables at the end of
Chapter 3.
Warning!