Scanlab RTC 5 PC Interface Board Installation And Operation Manual page 145

The example diagram in figure 53
nonlinearity curve can be determined.
Laser
power
P
1
P
1r
P
0
P
2r
P
2
0 S S
2k 2
Laser power progression – example of determining a nonlinearity
curve
The straight line in the diagram describes ideal linear
behavior in the relationship between laser power and
the laser control signal parameter (here, the term
laser power also represents the pulse frequency =
0.5/LaserHalfPeriod). The curved line is an example
of a realistic relationship: here, the laser power
rises/falls more slowly than the signal parameter.
S is the signal parameter value defined as the 100%
0
value and P is the associated laser power. At point
0
 P
(S ), the two curves intersect (this corresponds to
0 0
the data point Percent0 = 100, Scale0 = 1.0).
An increase (decrease) of the signal parameter to S
(S ) results in an ideal laser power P
2
laser power P (P ). For the actually desired laser
1r 2r
power P (P ), a corrective signal parameter value S
1 2
(S ) is needed. In this example, the following two
2k
value pairs would then be entered as data points for
the nonlinearity curve:
Percent1 = S /S · 100 = P
1 0
Scale1 = S /S
1k 1
Percent2 = S /S · 100 = P
2 0
Scale2 = S /S
2k 2
®
RTC 5 PC Interface Board
Rev. 1.9 e
7 Basic Functions for Scan Head and Laser Control
illustrates how the
Ideal
curve
Real
curve
S S S
Signal
0 1 1k
53
1
(P ) and a real
1 2
1k
/P · 100
1 0
/P · 100
2 0
145