Anritsu MS9740B - Page 39

1.3 Glossary
1-11
1
Outline
Wavelength Resolution
Wavelength resolution (Res) is the ability to separate two adjacent optical
wavelengths. Figure 1.3-5 thru Figure 1.3-7 show the changes in
half-width when changing the resolution, if measuring a light source with
a narrow spectrum such as a laser. The resolution must be set depending
on the required measurement wavelength resolution. The actual
resolution displayed on the screen is determined by integrating the levels
of the optical spectrum of single wavelength light source with sufficiently
narrow linewidth compared with resolution of the MS9740B and dividing
by the peak level. The values used in the calculation are the defaults
values at factory shipment or the values measured by executing
resolution calibration. For the resolution calibration method, refer to 3.1
“Calibrating Before Measurement”.
Figure 1.3-5 Measurement Example of Resolution 0.1 nm
Figure 1.3-6 Measurement Example of Resolution 0.5 nm
1550 nm
0.2 nm/Div
1551 nm
In Air
1552 nm
0
Half-width 0.095 nm
100 µ
W
50 µ
W
Res 0.1 nm
REF
Setting resolution
1550 nm
0.2 nm/Div
1551 nm
In Air
1552 nm
0
100 µ
W
50 µ
W
Res 0.5 nm
REF
Half width 0.505 nm
Setting resolution