Etalon Adjust

As of Motor Controls version 3.3.3.3 Etalon Adjust has been merged in with the Motor Controls program.

Etalon Adjust is required by our single-mode systems and provides automated mode stabilization. The Etalon Adjust program provides computerized adjustment of the OPO/OPA’s main cavity length to maintain single-mode laser operation. Adjustment is done using a combination of frame capture of the etalon’s interference rings and control of a piezo actuator. This ability is based on the inherent single- dual- mode nature of the OPO/OPA design. As the main cavity can support either mode or both simultaneously it is possible to cause complete cancellation of one mode by tuning the cavity length.

Fringe ring detection is accomplished in software by defining a region of interest (ROI) where the curvature of the rings is negligible. The raw data of the ROI is then examined and the pixels values summed into columns. The column with the greatest value (main column) is identified and any fringe rings within a user-defined region surrounding this main column are identified. Whether the fringe ring is to the right or left of the main column indicates the necessary voltage adjustment for the piezo controller.

Version History

• 1.0.0.0(March 25, 2011)Initial release.