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T-Cube NanoTrak Autoalignment Controller
Using the Range and Relative Signal Bars.
The Range and Relative Signal Bars should be considered together.
The Range bar displays the current range of the internal power meter. Available
ranges are as follows:
RANGE 1
30 nA full scale
RANGE 2
100 nA full scale
RANGE 3
300 nA full scale
RANGE 4
1 µA full scale
RANGE 5
3 µA full scale
RANGE 6
10 µA full scale
RANGE 7
30 µA full scale
RANGE 8
100 µA full scale
RANGE 9
300 µA full scale
RANGE 10
1 mA full scale
RANGE 11
3 mA full scale
RANGE 12
10 mA full scale
Note that in many practical arrangements the lower ranges may be unusable with
typical signal to noise ratios.
The Relative Signal Bar shows a convenient visual indication of the feedback signal
level. In this example, the input source is a TIA (PIN) type detector, and in this case
the bar display indicates the power level (in Amps) with respect to the currently
applied range, e.g. if the range is 1mA (Range 10), then a bar displaying half length
equates to a current power level of 0.5mA.
Note
. If the input source is set to SMA (voltage), for use with an external power meter,
then the bar display indicates the voltage being measured, 10V full scale; e.g. for an
input voltage of 5V, the bar displaying half length - see Section 6.2.2. for more details
on setting the input source.
9) Continue to adjust the manual actuators until the Range and Relative Signal bars
show a significant increase in the power level (i.e. well above the background
noise level).
10)Press the ‘Track’ button on the GUI panel to select ‘Track’ mode, i.e. the button
LED is lit.
The NanoTrak unit now takes over the search, and controls the piezo units to drive
the stage to the maximum power position.
11)Depending on the range of travel o f the piezo actuators, it is po ssible that the
piezo range is not sufficient to drive this stage to the max p ower position and in
