Here - PMOD/WRC

The commercial radiometers were selected for extended
frequency response at the highest, 10 10 V/A signal, gain.
The electronic and thermal time constants were determined
from frequency dependent signal gain measurements.
Figure 3 shows that the responsivity roll-on originating
from the differentiating time constant m 4 can cancel the
responsivity roll-off produced by the integrating time
constant m 2 , resulting in a m 3 = 109 Hz upper roll-off
frequency (produced by the remaining integrating time
constant).
responsivity in the center area which makes it possible use
of this detector in radiant power measurement mode with
low uncertainty. A temperature coefficient of responsivity
of 0.19 %/degree C was measured for the commercial
pyroelectric detectors with a relative expanded
measurement uncertainty of 20 % (k=2).
-2
-2 -1 0 1 2
-2
11000
-1
1.005
1.005
0.989
1.001
1.009
1.001
-1
Responsivity (V/W)
10500
10000
9500
9000
9570 Mid IR
9532#2 Mid IR
9570 Near IR
9532#2 Near IR
PD2
Ge
LiTaO3
LiNbO3
9570
9532#2
8500
0 5 10 15 20
Z (mm)
0
1
2
1.001 1.001
1.005
1.013
0.997
1.001
1.001
1.005
0.993 1.005
0.989
0.997
0.997 1.009
0.993
1.001 0.993
1.001
0.993
1.013
1.005
1.001
1.005
1.001
0.997 1.005
1.017 1.005
0.997
1.009
1.001
-2 -1 0 1 2
Y (mm)
0
1
2
Wavelength (µm)
0.985 0.995 1.005 1.015
Fig. 2. Spectral power responsivity of two pyroelectric
detectors. The individual points with error bars are values
obtained with laser sources at 1.32 µm and 10.6 µm.
Fig. 4. Spatial non-uniformity of responsivity of one of the
paint coated pyroelectric detectors at 10.6 µm.
60
50
40
30
20
curve fit
y = m1*sqrt(1+(M0/m4)^ 2)/sq...
Value Error
m1 51.909 0.10293
m2 16.382 2.4324
m3 109.48 0.74746
m4 15.814 2.3317
Chisq 0.30304 NA
R 0.99988 NA
10 100
Frequency [Hz]
References
[1] Eppeldauer G. P., Rice J. P., Zhang J., and Lykke K. R.,
Spectral irradiance responsivity measurements between 1 µm
and 5 µm, SPIE Proc. Vol. 5543, pp. 248-257, 2004.
[2] Larason T. C., Bruce S. S., and Parr A. C., Spectroradiometric
Detector Measurements, Part II – Visible to Near-Infrared
Detectors, NIST Special Publication 250-41, February, 1998,
U.S. Government Printing Office, Washington, DC.
[3] Lehman J., Eppeldauer G., Aust J. A., and Racz M.,
Domain-engineered pyroelectric radiometer, Applied
Optics, Vol. 38, No. 34, p. 7047-7055, 1999.
[4] Gentile T. R., Houston J. M., Eppeldauer G., Migdall A. L.,
and Cromer C. L., Calibration of a pyroelectric detector at
10.6 µm with the NIST High-Accuracy Cryogenic Radiometer,
Applied Optics, 36, p. 3614-3621, 1997.
Fig. 3. Frequency dependent responsivity of a pyroelectric
detector at a signal (current) gain of 10 10 V/A.
The spatial non-uniformity of responsivity was measured
at 10.6 µm. The results in Figure 4 show that the
commercial device has a roughly 1 % spatial variation of
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