MX10C, MX40C Series of Optical Transmitters
Chapter 4: Operating Instructions
Rev. F, February 21, 2020
Page 17
Figure 25
Changing the Fine-Tuning Step Size
Note that while the L-band and C-band lasers can hav
e their frequency adjusted by increments as small as 1 MHz, the laser’s
actual tuning accuracy is not this fine. See Section 5.6 below for more information.
To turn the dither setting on or off, tap on the DITHER row and use the ON or OFF buttons to change the setting, or the red
cancel button to abort the change.
Figure 26
Enabling and Disabling Laser Dither
Figure 27 shows laser frequency noise as a function of optical frequency when the laser is operated with and without dither
enabled. The red trace shows low noise operation when dither is turned off. Wavelength stability is improved by operating with
dither, but the blue trace shows that this comes at the expense of added noise.
Figure 27
FM Noise Spectrum of the Laser
FM Noise Spectrum with and without dither.
Wavelength stability is improved with dither,
but at the expense of adding noise (blue line).
Red line shows Low Noise operation with
dither turned off.
Use these buttons to toggle
the dither function On/Off.
In "STEP 1GHz" mode you can
edit the fine-tuning frequency
offset in steps of 1 GHz.
