Newport LDC-3706 Series, User Manual

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December 2019 17 LDC-3706 Series Laser Controller
Connecting to the Laser Controller
When connecting the laser or any other sensitive devices to the LDC-3706 Laser Controller, ILX
recommends that the instrument be powered up and the LASER output be in the off position
(with the ON indicator LED unlit). In this condition, a low impedance shunt is active across the
output terminals. When disconnecting devices, it is necessary to turn the LASER Output off, but
the instrument may be left powered on.
ILX also recommends that the connections to the LDC-3706 output be made using twisted pairs
with an earth-grounded shield (See Figure 2.1 below). The output terminals of the instrument
are left floating with respect to earth ground to suppress AC power-on/power-off transients that
may occur through an earth-ground referenced path. If the output circuit is earth-grounded at
any point (such as through the laser package and mount), the user must be careful to avoid
multiple earth ground in the circuit. Multiple earth grounds may provide circuit paths that induce
spurious currents in the photodiode feedback circuit and output leads.
Figure 2.1 - Laser Diode Connection Configurations