Calibration, Maintenance, and Troubleshooting
1919-R User Manual
92
12.2.2
Volume Absorbers
PF (High Energy High Average Power) Absorber
The newest PF type absorber has a high damage threshold for short pulses and can stand relatively
high average power density as well. In addition, it is able to be deposited on large areas, so it is the
absorber of choice for many applications.
Figure
12-1 Absorption vs. Wavelength of Various Thermopile Sensor Absorbers
Newport power/energy meters with the BB or PF type absorbers are individually calibrated by
laser at several wavelengths against a NIST calibrated standard meter. The meter can be switched
to give the exact calibration at the various wavelengths (532, 1064, and, where applicable, CO2).
Since the sensitivity changes little with wavelength, the user can use the settings closest to the
calibration wavelength with little error.
12.2.3
Linearity and Accuracy of Newport Thermopile Sensors
Linearity
The linearity of most Newport Thermopile detectors is specified to be 1% over the specified power
range of each particular instrument and is tested by Newport from time to time. The linearity is
generally tested against another sensor that has been NIST tested for linearity. For those models
for which the linearity is not tested over their entire range, randomly chosen sample models are
tested periodically over their entire range. The test is performed with a high power laser that can
cover the entire detector range using a beam splitter and lower power sensor that has previously
been tested for linearity for comparison. Thus, in all cases, the linearity of the detectors is
traceable to NIST measurements.
Method of Calibration
The absorption of the various Newport Thermopile absorbers can vary from disc to disc.
Therefore, all Newport absorbers are individually calibrated against NIST traceable standards.
