Tektronix SD-42, Руководство пользователя

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Operating Basics
2–2
SD-42 & SD-46 User Manual
Mean Power Monitor
The SD-42/46 Mean Optical Power Monitor allows you to monitor the mean
optical power coupled into the optical input using a digital voltmeter. The two
2 mm MONITOR sockets on the front of the SD-42/46 can be connected to most
common digital voltmeters using the two 2 mm to 4 mm cables supplied with the
SD-42/46. The monitor has two ranges, 1 V/
m
W and 1 V/mW (calibrated at
1300 nm for single-mode fibers) enabling mean optical input powers from 5 nW
to 5 mW to be measured.
NOTE
. The signal output of the SD-42/46 must be connected to a sampling head
or a 50
W
terminator for the power monitor to function.
Buttons and Lights
The front panel of the SD-42/46 has a SELECT RANGE button and two
range/range overload indicator lights. Pressing and releasing the SELECT
RANGE button changes the range of the mean power monitor. The range
indicator light glows green beneath the chosen range on the front panel, either
1 V/
m
W and 1 V/mW. If the mean optical input power is above the maximum for
that range (that is, 5
m
W for the 1 V/
m
W range or 5 mW for the 1 V/mW range)
the green light will be replaced by a red range overload light. If the red light is
illuminated while the monitor is in the 1 V/
m
W range, press the RANGE
SELECT button to change the monitor to the 1 V/mW range. If the red light is
illuminated in the 1 V/mW range, an optical attenuator should be fitted in the
optical path before the converter. Under overload conditions, the output signal
from the SD-42/46 may be degraded, and the mean power monitor reading will
be meaningless.
CAUTION. Under no circumstances should optical powers above 10 mW mean or
75 mW peak be applied to the input of the SD-42/46 Optical-to-Electrical
Converter Head.
Calibration
The SD-42 Optical-to-Electrical Converter Head is calibrated for response to
optical signals with wavelength of 1300 nm
±
20 nm. Optical signals with
wavelengths in the range of 1000 nm to 1700 nm can be analyzed using the
SD-42 with the responsivity as a function of wavelength being given in