EXFO T100S-HP Essential, User Manual, Page: 35 / 70

Changing the Optical Output Power and Diode Current
T100S-HP User Guide 35
5.3 Disabling/Enabling Active Cavity Control
Subject The T100S-HP is equipped with on-board active cavity control.
When you turn on the T100S-HP after the initialization routine is complete, the system
switches automatically to APC (constant power) mode with active cavity control (the
APC LED is on).
Active Cavity Control Requirements
Active cavity control is enabled if the following requirements are both met:
• APC (constant power) mode (APC LED on)
• Power > 0.8 mW
System Status
System status is summarized in the following table:
Table 10: Active Cavity Control - System Status
Procedure • To disable active cavity control, press the 2nd + APC key combination.
The APC LED blinks.
If you press the APC key and the APC LED goes off, this indicates that the system
has switched in constant current mode. When entering constant current mode, the
active cavity control becomes disabled, and the system restores the operating
parameters that were in effect at the time the T100S-HP last left the constant current
mode.
• To enable active cavity control, press the 2nd + APC command keys again.
If the APC LED starts blinking while the T100S-HP is in APC mode with active cavity
control on, this may indicate that the laser power output (P) is set to a value lower
than the 0.8 mW threshold.
APC LED Constant Power Mode Active Cavity Control
On Yes Yes
Blinking Yes No
Off No No