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Measurements Applications
Measuring Signal-to-Noise Ratios
User-entered
wavelength
When the signal-to-noise “user” function is selected, the Keysight 86120B uses only
one wavelength to measure the noise power for all signals. This wavelength is set by
the user and all signals are compared to the noise level at this wavelength to deter-
mine their corresponding signal-to-noise ratios.
Noise bandwidth
When measuring noise power, the Keysight 86120B must account for the noise
bandwidth used during the measurement. Because noise bandwidth varies with mea-
surement bandwidth (a wide bandwidth allows more noise to the Keysight 86120B’s
detector than a narrow bandwidth), the Keysight 86120B normalizes all noise power
measurements to a bandwidth of 0.1 nm. The annotation
0.1 nm
is displayed to
show that the noise bandwidth is being normalized to a 0.1 nm bandwidth.
To measure signal-to-noise
1
Press the front-panel Preset key.
2
Press List by WL or List by Power
.
3
Press Appl’s and then
S/N
.
Repetitive data formats
The Keysight 86120B signal-to-noise application works best when the laser
being tested is not modulated, or modulated with non-repetitive data formats.
With repetitive data formats, such as PRBS data and SONET formats, there is
significant low-frequency amplitude modulation of the laser. This modulation
raises the noise floor of the Keysight 86120B significantly. The signal-to-noise
measured can be limited to about 15 dB while measuring lasers modulated by
repetitive data formats. For improved performance when the laser is modulated
with repetitive data formats, use the Signal-to-Noise with Averaging applica-
tion.
Содержание 86120B
Страница 1: ...Keysight 86120B Multi Wavelength Meter User s Guide...
Страница 2: ......
Страница 3: ...1...
Страница 12: ...10 General Safety Considerations...
Страница 68: ...You can use the ABORT and CONT softkey to stop and restart a print job that is in progress...
Страница 100: ...98 Programming Monitoring the Instrument...
Страница 163: ...161 Programming Commands CALCulate1 Subsystem Query Response For normal update 34123 For fast update 4268...
Страница 231: ...229 Performance Tests Test 5 Amplitude Accuracy and Linearity...
Страница 232: ......
Страница 233: ...7 Definition of Terms 233 Specifications 235 General Safety Information 239 Specifications and Regulatory Information...
Страница 244: ...242 Specifications and Regulatory Information Product Overview...
Страница 250: ...248 Reference Menu Maps Display List by Power Menu Display List by WL Menu...
Страница 251: ...249 Reference Menu Maps Delta On Menu Delta Off Menu...
Страница 253: ...251 Reference Menu Maps System Print Menu...
Страница 254: ...252 Reference Menu Maps System Setup Menu...
Страница 272: ......