Tsunami - Beckman Institute Laser Resource Center

Lok-to-Clock Electronics
Figure 8-9: Typical Cross-correlation Signal for a LTC Tsunami Laser
and Mode-locked Laser. AT = 2.4 ps FWHM.
Operating a Model 3950Dl3960D
Without the Model 3930
Refer to Figure 8-10 for pin descriptions of the D-sub Lok-to-Clock
Tsunami To 3930 connector. It also shows the schematic for the Mi limit
switch optointermptor electronics incorporated in the Tsunami.
To set the position of Mi, the coarse cavity length control, apply a 0 to
+ 10 Vdc signal across pins 13 and 2 to lengthen the cavity and reduce the
frequency, a 0 to - 10 Vdc signal to shorten the cavity and increase the
frequency. To set the position of PZT-driven mirror M4, the fine cavity
length control, apply a 0 to 100 Vdc signal across pins 8 and 1 to modify
the position of PZT mirror M4. In most cases, unless you also provide a
closed-loop feedback circuit for monitoring power output, driving the M4
PZT mirror is not recommended and serves little purpose. If you need this
high-speed noise reduction, you should upgrade your system to a Model
3950Cl3960C and purchase the Model 3930.
WARNING
You must employ the limit switches if you intend to drive Mi. This
insures the motor drive mechanism will not be damaged if you exceed
the drive limits. Any such damage is not covered under your warranty!
When operating between end limits, the limit switch signals UpLim and
DnLim are high. A low signal indicates the limit has been reached. A
suggested motor drive circuit is shown in Figure 8-1 1 which includes