3.5 Constant power mode (CONST P)
LDC2xx / page 18
If the connection to the laser diode is in terrupted during operat ion the laser diode
current is switched off autom atically. LED "ON" (L8) ex tinguishes, LED "OPEN" (L6)
lights up and a short beep is heard as warning signal.
If the output is switched on wh ile the interlock is closed and there is no laser diode
connected at first the LED "ON" (L8)
lights up and the output is switched on.
Immediately afterwards the LDC2xx rec ognizes the missing of the laser diode and
switches the output off.
The LED "ON" (L8) extinguishes and the LED "OPEN" (L6) lights up.
After pressing "ON" (L9) the LED "OPEN " (L6) extinguishes and the output can be
switched on again by pressing "ON" (L9).
If a photodiode is connected the displa y can show the photodiode current "I
PD
" or the
optical power "P
LD
" by pressing the keys (L18) or (L19).
The laser current can be modulated via t
he connector "MOD IN" (R3) (refer to
chapter 3.7).
3.5 Constant power mode (CONST P)
With a photodiode connected the laser diode c an also be operated in constant power
mode:
Start operating the LDC2xx in constant current mode (refer to chapter 3.4)
Select the display "I
PD
" with the buttons (L18) or (L19).
Check whether an appropriate laser diode current "I
PD
" is available. A photodiode
current of at least 5 µA must be available for a stable operation of the power control.
NOTE:
With negative signs of the photodiode current "I
PD
" the photodiode must
be reverse connected.