Tsunami - Beckman Institute Laser Resource Center

Tsunami
Table 7-1: Bi-fi Selection for Broad Picosecond Operation
Blue
< 20 ps
2 20 ps
Standard
< 20 ps
2 20 ps
Mid-range
< 20 ps
2 20 ps
Long
< 20 ps
2 20 ps
X-long
< 20 ps
2 20 ps
Bi-Fi Type
2-plate
3-plate
2-plate
3-plate
2-plate
3-plate
2-plate
3-plate
2-plate
3-plate
Bi-Fi Dot Color
Yellow
Green
Yellow
Green
White
Orange
Yellow
Green
Yellow
Green
6. Verify the beam is in the center of MI0. Adjust M5 if necessary.
7. Again, refer to "Optimizing Laser Output" earlier in this chapter to
"walk the beam" and optimize laser output.
8. Adjust the bi-fi for the desired wavelength.
Part Number
0434-8953
0434-8973
0434-8953
0434-8973
0434-8954
0434-8974
0434-8953
0434-8973
0434-8953
0434-8973
Purge the system with clean, dry nitrogen gas when you are operating
within water and oxygen absorption regions (Figure 7-1).
9. Push the STATUS mode locker enable button (the ENABLE LED should
be lit).
10. Set up an autocorrelator such as the Model 409 -08 according to its
user's manual, then maximize the signal by adjusting the angle of the
nonlinear crystal for the optimum phase-matching condition.
11. Maximize the intensity of the autocorrelated waveform by adjusting
the coarse and fine PHASE controls.
Refer to chapter 6, "Alignment: Coarse Phase Adjustment ...," for
infomation on setting the coarse and fine PHASE controls.
12. Adjust the GTI POSITION control to obtain a pulse.
13. Optimize system performance by iterating between the following
adjustments:
a. Adjust the fine PHASE control.
b. Adjust ion laser output power to obtain a stable pulse.
c. Adjust the GTI POSITION control for the desired pulse width.