Spectra-Physics Tsunami - Converting between Fs and Ps Configurations; Requirements for Conversion

Tsunami Mode-Locked Ti-sapphire Laser
6-34
5. Adjust M
3
to center the beam on the OC.
6. Iterate adjustments of the end mirrors to optimize output power while
adjusting M
3
to keep the beam centered on the OC.
7. Verify the laser beam is centered on mirrors M
1
to M
5
, as well as M
10
.
Adjust the photodiode pc board if required (refer to the earlier section
on pc board alignment in this chapter).
Converting Between fs and ps Configurations
The following procedure assumes you are converting between fs and ps
configurations using either the same optics set or a set that overlaps the
wavelengths of the current set.
If changing optics sets, unless you are certain the optics are clean, clean
each one as it is placed into the laser. Refer to Chapter 9, “Maintenance,”
for information on cleaning optics.
The Tsunami laser comes in several configurations. Please refer to “System
Configurations” in Chapter 1. Some of these systems can be converted,
most cannot without being upgraded at a Spectra-Physics service facility.
Check with your service representative before attempting to convert your
system.
Requirements for Conversion
Tsunami ps and fs lasers are inherently different, and various mounts, com-
ponents, and optics must be changed when converting them from ps to fs
operation, or vice versa. These two systems differ in three ways:
• the transmission of the output coupler.
• the method of wavelength selection: a birefringent filter (bi-fi) for ps
versions and a slit for fs versions.
• the method of dispersion compensation: a Gires-Tournois interferome-
ter (
GTI) for ps versions and a prism sequence for fs versions.
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.
Caution!