Download Optical Fan Out

NLC Timing System
Optical Fan Out
Overview
This system is configured as a single width VXI module.
The Optical Fan Out module receives an optical input RF signal or Timing Signal,
amplifies it and fans it out eight (8) ways. The unit is used for short runs where stabilized
links are not required. A semiconductor amplifier and fan-out is used. The input and
output power levels are monitored, and the gain of the module is adjustable.
Functional Description
The module receives the NLC Timing System RF clock on a fiber input. This optical
signal is coupled (-10 dB) to an optical power detector which converts the clock and
fiducial pulse to an electrical signal. The resulting electrical signal is amplified and fed
to a peak detector, whose output is sampled by an Analog To Digital Converter (ADC).
The output of the ADC is stored by the local microprocessor.
A Semiconductor Amplifier (Gain of 10 dB), drives a one-to-eight (1:8) Fiber Fan Out
through a (-10 dB) coupler. The Fiber Fan Out drives the module’s eight outputs through
the front panel. The coupled output of the 10 dB coupler drives an optical power
detector, whose electrical output is amplified and peak-detected, then sampled by the
ADC.
The local microprocessor’s program continually compares the input and output optical
power levels, and controls the Semiconductor Amplifier’s Bias and Temperature to keep
the Optical Fan Out module’s output at a constant level.
The microprocessor also interfaces to the VXI backplane through some glue logic, for
remote status and commands.
OFO.doc
05/10/17
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