Performance Verification
14
SD-44 Instruction Manual
NOTE
. The longer wavelengths of 1310 nm and especially 1550 nm in single
mode fiber are sensitive to loss in fiber due to bending of the fiber. The fiber
bend radius of the SD-44 fiber input should lay with >1.5 inch bend radius
along the fiber’s entire length. Although this precaution must be maintained
throughout the entire performance verification procedure, it is especially
important for this step in order to accurately adjust and measure the DC
conversion gain of the SD-44.
2. Connect the optical attenuator output to the optical power meter using single
mode optical cable with FC connectors. Use the appropriate optical power
meter sensing head with calibrated measurement for a wavelength span
including 1310 nm and 1550 nm. Be sure the optical power meter wave-
length setting and optical attenuator setting is at 1310 nm. Enable the optical
output.
3. Adjust attenuator or the optical source so that the power meter reads
200
m
W.
4. Move the FC fiber end (the one now adjusted to 200
m
W average power)
from the optical power meter and connect it to the SD-44 input under test.
5. Attach voltmeter with 50
W
termination to SD-44 output.
6. Record the voltmeter reading. The 1310 nm Conversion Gain in units of
V/mW is
(voltmeter reading)
×
5
7. Record the 1310 nm conversion gain on the test record.
8. Disconnect the 1310 nm laser from the optical attenuator, and reconnect the
1550 nm laser source. Set the optical attenuator to the correct wavelength.
NOTE
. Do not disturb the fiber connection between the optical attenuator output
and the SD-44 input!
9. Adjust the optical attenuator until the voltmeter reading is the same as in
step 6 above
±
1%.
10. Without moving the optical attenuator from the position in the previous step,
disconnect the output fiber of the optical attenuator from the inline adapter
with the SD-44 and insert the optical attenuator output into the optical power
meter.