6
ISOMET
Observe the diffracted first-order output from the acousto-optic modulator and the undeflected
zeroth order beam. Adjust the Bragg angle (rotate the deflector) to maximise first order beam
intensity.
3.14
After Bragg angle has been optimized, slowly increase the RF power until maximum first
order intensity is obtained. Record this intensity value (I
SAT
).
Typical values:
Class Method description
Setting
UpdateDDSPowerLevel
80%
UpdateRFAmplitude Wiper
60%
3.15
To equalise deflection efficiency across the extremes of the scan, alternate between the
minimum and maximum desired frequencies (e.g. 50MHz and 90MHz input resp
’) and adjust
the PHASE and AMPL values to give the same efficiency at both positions. Fine tuning of the
incident Bragg angle and RF power may be necessary for optimum results.
3.15
The amplifier is now ready for use.
Please contact Isomet for further guidance and example programs
