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Measurements in Photonics
Measurements in Photonics 235
Polarized at 45°
100
90 Reflectance of Aluminum
80 DIFFRACTION GRATING
EFFICIENCY FOR RELATIVE
70 COMPARISON ONLY
Efficiency, % 60
50
40
30
20
10
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6
Wavelength, m
1st Order
Cat. No. 35-53-15-280 Date 8-22-87
Serial No. 2855-42-1 Blaze Angle 17°27’
Grooves/mm 1200 Blaze Wavelength 5000
Remarks
(c)
Figure 10.6. (c) Blaze wavelength 500 nm, 1200grooves/mm.
on the mirror surface, always wear gloves while handling mirrors.
During use, the mirror surface will naturally attract dust particles
from the air. Attempting to clean this dust from the mirror by blowing
or scrubbing the mirror will result most often in damage to the mirror
by grating scratches or leaving behind debris on the metal surface. In
most cases you will not improve the quality of the measurement.
Thus, it is recommended that you keep the monochromator closed,
and that you do not attempt to improve your measurements by clean-
ing the components.
10.6 The Spectrometer/Monochromator System
In Figs. 10.7 and 10.8 you can see the interior of two typical designs
for these instruments. Figure 10.7 is called a Czerny–Turner grating
monochromator. It corresponds closely to the diagram shown in Fig.
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