Hi Andyf97, I mount the diodes in basically a fairly big aluminium block which helps suck the heat away from the laser chip, I have not really got into peltier coolers maybe one day but for the moment it is unnecessary for me. Most frequent damage is done to the chip face when going well above the specified current levels recommended by the laser manufacturer. Obviously cooling by external means would help reduce this but inevitably if you crank up the power enough the chip literally cooks itself from the inside destroying the polished output face. The only temperature checks I have done with pioneer diodes was on the outside of the aluminium block which realistically is no good as the diode temp could be 20 to 30 degrees hotter than this, as you have seen for your self the little wires that connect up the diode for power can melt this is more of a manufacturing fault more than anything as the wire should be made to the correct tolerance levels to take the current that is applied to the chip, again cooling and using a inert gas would help to what degree I have know idea but high power pump chips are cooled for that reason as it would not belong before you had a thermal run away condition, I would be very surprised if running the diodes at the manufacturers guide line maximum would melt the wires but I am no expert in such matters. Nice shows by the way.
Paul