Photodiode Sensors
1919-R User Manual
38
6.1
Operation of 1919-R with Photodiode Sensors
To use 1919-R with Photodiode sensors:
1.
Connect the Photodiode sensor to the 1919-R meter: Insert the 15 pin D type connector of the
measuring sensor cable into the socket marked
Sensor Input
on the rear panel of the 1919-R
meter. 1919-R will reconfigure itself to work with the attached sensor.
2.
All of the sensor’s measurement parameters are shown on the main screen. (These are also
available when you press the
Menu
button and select
Sensor
). Use the Navigation keys to
navigate to the parameter you want to change.
3.
Use the up (
↑
) /down (
↓
) Navigation keys to select the parameter to change and press the
Enter
key. Change the setting with the Navigation keys.
4.
Press the
Enter
key to save the settings.
Note:
The 1919-R automatically saves the current settings for the next power up.
Warning:
Do not exceed maximum sensor limits for power, energy, power density, and energy
. Otherwise, there is a risk of damaging the absorber.
6.2
Measuring Laser Power with Photodiode Sensors
The following procedure describes how to use Photodiode Sensors to measure laser power. (The
power is measured 15 times per second.) You can specify the expected laser
Range
,
Laser
setting,
whether the
Filter
is IN or OUT as physically configured on the sensor, and the
Average
power
period.
Photodiode sensors have a different sensitivity at different wavelengths. Moreover, the filters
used in the sensor have a different transmission at different wavelengths. In order to compensate,
each sensor has a built in calibration curve (with 1nm resolution) over the entire measurement
range.
When you choose the correct laser setting, the correction factor for that wavelength is
automatically introduced. Note that the laser setting presently corrected for is displayed in the
upper left portion of the display.
Photodiode sensors can measure a maximum power of about 10mW, depending on the model.
Many models are equipped with filters that extend the range by 10x, 100x, or 1000x, depending
on the filter type in use. The 918D series photodetectors have a built-in optical attenuator, which
can be manually switched into or out of the optical path using a thumb-wheel located on top of
the detector housing. Attenuator ‘ON’ and ‘OFF’ markings indicate the turning direction. A built-in
sensor automatically detects the attenuator position, signaling the instrument to use the
appropriate responsivity for the detector/attenuator combination.
Depending on what powers you wish to measure, choose whether to work with the removable
filter installed or not. For this purpose, the 1919-R has a "filter" setting and uses the proper
correction curve depending on whether the filter is installed.
To set measurement parameters for laser power when using Photodiode sensors:
1.
The measuring mode is
Power
.
2.
Set
Range
to
dBm, AUTO
, or to one of the manual ranges, as follows:
dBm
: Logarithmic scale, where dBm units are defined as: 10 x log (reading in mW). At 1mW
the reading will be 0 dBm, at 100mW it will be 20 dBm, and so on.
