60
Using the Multi-Wavelength Meter
Measuring Modulated Lasers
Measuring Modulated Lasers
Lasers modulated at
low frequencies
A laser that is amplitude modulated at low frequencies (for example, modulated in
the audio frequency range) can cause spurious wavelengths to be displayed below
and above the correct wavelength. The power of these spurious wavelengths is
below that of the correct wavelength. These spurious signals can be eliminated by
decreasing the peak threshold.
Refer to “Defining Laser-Line Peaks” on page 52
Even when the laser is amplitude modulated, the correct wavelength and power is
displayed.
The spurious wavelengths caused by low frequency amplitude modulation will be
located above and below the correct wavelength by the following wavelength spac-
ing:
where F is the modulation frequency in Hz, and
λ
is the correct wavelength in nm.
For example, an amplitude modulation of 10 kHz on a 1550 nm laser will produce
spurious wavelengths spaced by 15 nm from the correct wavelength, and the spuri-
ous wavelengths will be at 1535 and 1565 nm.
Low frequency (10 kHz) AM modulation graph showing rounded sideband spurs.
spacing
6
10
–
×
10
F
λ
2
=
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...
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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: ......