Tsunami - Beckman Institute Laser Resource Center

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Controls. Indicators and Connections
Opto-Mechanical Controls
fs Configuration
Rod translation control-vertically translates the Ti:sapphire rod in a
plane parallel to the face of the rod. Use it to maximize output power during
alignment. The dove-tail slide is held in place with two screws (refer to
Figure 6-5).
The following describes those opto-mechanical controls specific to
Tsunami lasers configured for femtosecond operation. Refer to Figure 4-3
and Figure 4-4.
Prl and Pr4 prisms-in conjunction with Pr2 and Pr3, compensate for
positive GVD in a fs system. Each prism mount has a translation adjust for
driving the prism into the beam path for fs operation, and completely out
of the beam path for ps operation. Once set, a setscrew on the slide locks
each in position. These prisms are absent in a Model 3950 ps-only laser.
WARNING
Prisms Prl and Pr4 are pre-aligned at the factory. DO NOT adjust these
prisms until specifically told to do so elsewhere in this manual.
M6 through M9 prism mirrors--direct the cavity beam from M5 through
the prisms and into the AOM. Each mirror has vertical and horizontal alignment
adjustments. The inside adjust is for vertical, the outside for horizontal.
Prism dispersion compensation control (Pr2 and Pr3)-used to adjust
prism-pair Pr2 and Pr3 for overall cavity dispersion balance and shortest
output pulse. It is used interactively with the nearby slit control. The
micrometer control is available when the laser head cover is in place. This
control is absent on the Model 3950 ps-only laser.
Slit wavelength selector-used to select laser wavelength. The micrometer
control is available when the laser head cover is in place.
Slit bandwidth selector-used to change the output pulse bandwidth.
This Allen screw adjustment is set at the factory for a specified output
depending on the optics set installed. Reset it if you change optics set. If
set too wide, it causes cw break-through; set too narrow, it limits
bandwidth and produces long pulses.
MI high reflector (HR) --one of two cavity end mirrors. It reflects all laser
light back into the cavity. The HR replaces the GTI used in the ps configuration.
Its vertical and horizontal adjustments allow you to align the laser
cavity and to optimize output power and mode quality. These controls are
available when the laser head cover is in place.