-- SebastianRabien - 15 Dec 2015

From time to time the Innolas lasers require a tuning of the SHG temperature to maintain the power level.

This should be done when over time the laser head drops in power. Tuning of the SHG temperature is done with changing the according parameter in RANGER, and observing the change in power in the Power Meter, or the online power measurement via the field cam. The latter is available in the Laser Controller. Following procedure must be followed:

  1. Log into dx-lalas or sx-lalas, depending on which side the laser to be tuned is located.
  2. Open firefox, go to monit and make sure that the LAS processes are active.
  3. Open the Laser Controller GUI: Use the corresponding icon or type in a terminal argos_dx_las_controller_gui
  4. Get the controller into the "STARTED_UP" state. [TBD: link to state machine info]
  5. For optimal results, let the lasers run for ~1 hour before continuing with the procedure.
  6. Check the laser power in the Laser Controller GUI. (Note: The power numbers are derived from the intensity of the field camera).
  7. Optional: Open zabbix to monitor the power trend.
  8. Open the Las Lab Eng GUI: Use the corresponding icon or type in a terminal argos_dx_las_lab_gui
  9. In the Las Lab Eng GUI, put the other laser heads in standby mode such that the power read corresponds only to the laser to be tuned.
  10. Start RANGER by opening a terminal in the corresponding lalas computer and typing ranger.
  11. In ‘Services’ double-click on DX_INNOLAS@, (or SX_* accordingly), then select Node browser to expand the selection.
  12. Expand DEV1 for Laser 1, or DEV2, 3 for Laser 2, 3 accordingly. Only work on one unit at the time to avoid any confusion!!!
  13. Open the following nodes:

* TUNING_IN_C (found when expanding "SET_SHG_TEMPERATURE_TUNING")
* SHG_TEMPERATURE (only for monitoring changes)

  1. First press the GET_SHG_TEMPERATURE_TUNING. The current value is shown in MEASURED_SHG_TEMPERATURE_TUNING. The value will be between 1.0 and -1.0.
  2. Type this value into TUNING_IN_C, press ENTER and click the green check mark button.
  3. Press the SET_SHG_TEMPERATURE_TUNING button
  4. Increase the value by 0.1, press ENTER and click the green check mark button. Press Set SHG Tuning to apply. You can and must only change by 0.1 each time. Min allowed value is -1.0, max value is 1.0.
  5. Wait for a while to check if the power increases or decreases. If it increases go on into this direction, otherwise start to decrease value. Continue until the maximum is found, be patient.
  6. Once the max power has been found, proceed to tune the laser current for max power. Then try tuning SHG again.
  7. If the laser max current was changed, commit changes with maintenance GUI into SVN (argos_dx_las_maintenance_gui).
Topic revision: r5 - 26 Jun 2018, GustavoRahmer
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