The ScanMate 2E version is equipped with an intracavity etalon (in the following named "etalon"), which is installed in the laser resonator to attain a narrower line width. The etalon is moved synchronously with the grating when a scan is executed.
There are two different operating modes possible here, which vary significantly in size of scan range. During an etalon scan (ES) grating and etalon are turned synchronously by the computer over a reasonable wavelength interval, whereby the positions required for etalon and grating are merely calculated after synchronization. Mechanical deviations are not corrected.
During a multiple etalon scan (MES) etalon and grating are re-synchronized by the computer after a step-by-step run through a defined scan range. The scan range is only limited by the tuning range of the dye. The computer evaluates a diode signal after each step (beam intensity, the sum of signals at Sensor A and Sensor B) to correct any deviations in synchronization. You chose between ES and MES by setting the parameter "Sensor" in the menu "Setting" "OFF" (ES) and "ON" (MES).