Hi,
... I've sourced some old PDT-lasers and out of curiosity opened the diode-modules to see what's inside.
Some of them were really astonishing in assembly and expense! -- attached images of the two most interesting types ...
One was a 5W@652nm-diode with a farfield showing, that this in reality is a fibercoupled multidiode-array with 25 or 75 emitters in a really small housing:
And another device with a testing list for 6Watts and a display-range from 0.1W to 5W had a 20Watt@652nm-module inside with 61! single fibercoupled diodes -- one separate as aiming laser, 60 connected in serie with 120Volts driving voltage! ... and on a gigantic cooler - 14 PTC's connected in series too!!
Viktor