Tektronix OM4006D, User Manual

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Operating basics
Power : Sets the laser power level. Type or use the up/down arrows to choose
the desired laser power level. The allowed power range is shown next to
the control.
Fine Tune : The Intel/Emcore lasers can be tuned off grid up to 12 GHz. This
can be done by typing a number in the text box or by dragging the slider. The
sum of the text box and slider values will be sent to the laser. Once the laser
has accepted the new value it will be displayed after the ‘=’ sign.
First Frequency : Not settable. This is the lowest frequency that can be
reached by the laser.
Last Frequency : Not settable. This is the highest frequency that can be
reached by the laser.
Channel 1 : Settable when emission is off. This is the de fi nition of Channel 1.
Grid Spacing : Settable (with 100 MHz resolution) when emission is off. 0.1,
0.05 or 0.01THz are typical choices. Use 0.01 THz if tuning to arbitrary
(non-ITU-grid) frequencies. Using this grid plus Fine Tune, any frequency in
the laser band is accessible.
Laser Electrical Power : This should normally be checked. Unchecking
this box turns off electrical power to the laser module. This should only be
needed to reset the laser to its power-on state, or to save electrical power if a
particular laser is never used.
Emission
: Click to turn on or off front panel laser emission.
Channel setting within the ITLA grid gives the corresponding frequency (in THz)
and wavelength (in nm). Power is set within the range allowed by the laser. It is
best to set the Signal and Reference lasers to within 1 GHz of each other. This
is simple if using the internal OM4000 instrument lasers: just type in the same
channel number for each.
If using an external transmitter laser, you can type in its wavelength and the
controller selects the nearest channel. If this is not close enough, try choosing a
fi ner WDM grid or use the fi ne tuning feature. If available, fi ne tuning of the
laser is done with the Fine Tune slider bar, and typically works over a range of
±10 GHz from the center frequency of the channel selected.
Certain laser models have a cavity lock feature that increases their frequency
accuracy at the expense of dithering the frequency; this feature can be toggled
with the Cavity Lock button. Cavity Lock is necessary to tune the laser, but can
be unchecked to suppress the dither.
22 OM4000D Series Coherent Lightwave Signal Analyzer