Chapter 2 Operations; Connecting To The Laser Current Source - ILX Lightwave LDC-3926339 User Manual

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C H A P T E R
O
PERATIONS
This chapter introduces the operation of the LDC-3926339 front panel control
functions. It offers instructions for connecting your laser to the current source. This
chapter also contains step-by-step procedures for operating your module in
Constant Current Mode or Constant Power Mode. ILX Lightwave recommends
you review the contents of this chapter before operating your Laser Diode
Controller.

Connecting to the Laser Current Source

When connecting your laser diode or any other sensitive devices to the LDC-
3926339, ILX recommends the instrument is powered up with the laser output
turned off. In this condition, a low impedance shunt is active across the output
terminals. When disconnecting devices, it is necessary to turn off only the laser
outputs.
ILX recommends the connections to the LDC-3926339 output be made using
twisted wire pairs with an earth-grounded shield (see Figure 2.1 on page 9). ILX
recommends using the CC-326H Current Source/Unterminated High Power
Interconnect cable with a braided outer shield designed to provide the best
possible rejection of most transient noise signals. The output terminals of the
instrument are left floating, relative to earth ground, to suppress AC power-
on/power-off transients that may occur through an earth-ground path. If the output
circuit is earth-grounded at some point (such as through the laser package and
mount), the user must avoid multiple earth grounds in the circuit. Multiple earth
grounds may provide circuit paths that induce spurious currents in the photodiode
feedback circuit and output leads.
If an inadvertent open circuit occurs during laser operation (while the laser is on),
your laser may be damaged by a momentary circuit break-and-remake before the
final circuit break. The LDC-3926339 has circuitry designed to detect open circuits
and shut the output off under most conditions. However, ILX recommends that
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LDC-3926339
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