First step in pulsing a pulsed laser diode
To obtain the short optical pulses, the
MOSFET gate has to be charged very fast.
The MOSFET has a gate capacitance of 300
pF. To obtain the required gate-source
threshold voltage of 5 V the gate must be
charged with about 7 nAs within several
nanoseconds. Therefore a pulsed trigger
current of about 1 A is required. Such a
signal can be generated by a high speed
power MOSFET driver IC which itself is
triggered by a TTL-level voltage signal.
As MOSFET driver we can suggest the
following types


Elantec EL7104C
Micrel MIC4452


The MOSFET inside the hybrid package is
the Infineon BSP318S .


It is rated for 18.5V on pin 2 and 15V on trigger pin 1.