Spectra-Physics Tsunami - Ps to fs Conversion Steps

Alignment
6-37
14. Place a white card outside the output window, and adjust M
5
to direct
the images onto the card. Use an IR viewer to see the fluorescent
images.
You should see a cross-shaped figure centered in a circular background
fluorescence. The fluorescence is created by the scattered light through
the
AOM and output coupler.
15. Remove
M
10
and replace it with the M
10
for ps operation.
16. Open the shutter.
17. Align M
10
.
a. Place a white card with a 2.5 mm diameter hole in it between M
4
and M
5
so that the hole is centered on the reflected fluorescent
image from M
4
.
b. Adjust M
10
vertically and horizontally to direct the reflected image
from M
10
back through the hole in the card and overlap it with the
image coming from M
4
.
To determine which reflected image comes from M
10
, watch the M
5
side of the card and slightly adjust M
10
until one image moves.
c. Remove the card; lasing should begin.
d. Adjust M
1
and M
10
to optimize Tsunami output power.
18. Verify the beam is centered on M
10
. If necessary, adjust M
3
to recenter it.
19. Optimize laser output.
Refer to Chapter 7, “Operation: Optimizing Laser Output.”
20. Adjust the photodiode pc board if required.
Because M
10
is wedge-shaped, the photodiode pc board might require
adjustment in order to maximize the photodiode signal (as seen on the
Model 3955 photodiode indicator). Refer to “Aligning the Photodiode
PC Board” earlier in this chapter.
21. Modelock the Tsunami.
Refer to Chapter 7, “Operation: Mode-locking the Laser.”
This completes the fs to ps conversion.
Ps to fs Conversion
The following procedure assumes you are using the same set of optics
(same wavelength set) or an overlapping wavelength optics set.
Verify the Tsunami is lasing prior to beginning this procedure.
1. Close the pump beam shutter and, for electrical safety, turn off the
Model 3955 electronics module.
The pc board on the floor of the laser head contains high voltage. Turn-
ing off the Model 3955 electronics module disables this board while you
remove the GTI.
Danger!