Photodiode Sensors
StarBright User Manual
43
shows a sample Bargraph showing laser power measurements, including
range, wavelength, filter, and average values. In this display, you can press
(Click the above links for more details.)
Figure
7-2 Photodiode Power Line Graph
7.3
Averaging and Measuring Very Low Power Measurements
If the laser power is fluctuating, the StarBright can display the average power readings with
averaging periods varying from 1s to 1 hour. When measuring very low powers, such as picowatt
measurements using the PD300-IRG or PD300-UV, there will be a rather large zero offset coming
from the detector as well as a considerable noise fluctuation. Nevertheless, you can measure
these low values by using the average function and pressing offset to eliminate the detector zero
offset.
To measure very low powers:
1.
Press
Menu
and select
Functions
. Choose the appropriate value you want to
Average
over,
save it, and then
Exit
.
1.
Block the power source you wish to measure, wait for a few measurement periods and press
Offset
to subtract the zero offset.
2.
Unblock the power source and measure.
For a detailed description of the average function, see
Note:
The Average function does not work with autorange or dBm scales.
