Green module solder mod = 40mW increase without podmodding

Just wanted to share an experiment with you that successed for me and increased the output power by about 40mW without potmodding it.

My goal was not to increase the output but to make it more stable by better cooling the cristals so they do not heat up that fast. in the past I successed by wrapping the brass part where the crisatals are glued in with some aluminium foil, but got the idea that solder can make the trick too and maybe even better than just using aluminium foil.

So the main idea was to solder the brass part where the cristals are to the brass part where the diode is screwed in.

First just at the places where the glue was missing. After that I removed the rest of the glue with a razor blade and applied there also some solder. This way I made sure the cristals are still in it´s position and the solder acts as a kind of heat transfer medium.

The brass parts got really hot while doing it, but I made sure the solder is just fluid where I currently applied it.


This was a really risky task with a brand new module I got from Lazerer.

Before the mode was done the module was peaking at 170mW and satteling at 160mW. After the mode was done it peaked at 220mW and satteled down at 200mW.


Oh well. On the pics below you see the expanding lens being glued directly on the brass part with the cristals. Its the first time I´ve seen this lens being mounted that close to the cristals.

The collimating lens had to be screwed all the way down to get it focused to infinity. This module gave a extremely thin beam but unfortunally not a very good divergence. I fixed this by removing the lens afterwards and using other parts with lenses from an other module I had here around.

If the higher output was due to improved heat transfer, the peak would not change. The temp of everything is at ambient right as you switch it on, both before and after your modification. Something else is at play here. I seriously doubt if you did this to many modules, your results would not be consistent.

Yes, you are right about everything being at ambient temp when I´m switching it on, but in a normal module where the brass with the cristals is just glued, it is heated up much much faster than the brass part with the diode and the housing. I checked this already with other modules before I got the idea to use solder by cooling the part with the diode. The part with the cristals got hot really fast though the doide was still cool. Thats why i wrapped them with some aluminium foil.

I´m not sure about this. Maybe you are right, but maybe the cristals are also heating up that fast in a normal module their efficiency already is decreasing before it peaks at it´s possible maximum.

All I just can say I wanted to get a more stable output but got not just a more stable output but it increased too and that´s the only explanation I can think of.

honeyx said:

Yes, you are right about everything being at ambient temp when I´m switching it on, but in a normal module where the brass with the cristals is just glued, it is heated up much much faster than the brass part with the diode and the housing. I checked this already with other modules before I got the idea to use solder by cooling the part with the diode. The part with the cristals got hot really fast though the doide was still cool. Thats why i wrapped them with some aluminium foil.

I´m not sure about this. Maybe you are right, but maybe the cristals are also heating up that fast in a normal module their efficiency already is decreasing before it peaks at it´s possible maximum.

All I just can say I wanted to get a more stable output but got not just a more stable output but it increased too and that´s the only explanation I can think of.

Click to expand...

Heatsinking only changes duty cycles not outputs right? Maybe it will be a little more consistent in the higher part of the duty cycle but a cannot think of a reason why the total power would increase

greetings,,

It is possible that the crystal were in less optimal configuration. By removing it and glueing it back on maybe it was set to optimal alignment. Sometimes just a few degrees makes a great difference. It can be pure luck.

Like I said. I just wanted to make it more stable and so of course increase the duty cycle and even wasn´t thinking about increasing the output. So this was also a big suprise to me.

Didn´t remove it at all. The glue is still there between both parts. I just removed carefully the glue at its edges to make place for the solder, but first after appling some solder where there was no glue at the edges. So all the glue between the two parts plus the small dips of solder I applied first kept it in it´s position.

I of course do have some experience in realigning the cristals like you can see here: http://laserpointerforums.com/f45/somepics-decanned-ir-diode-fixing-greenie-68486.html

but this time I was really careful not to change the aligment. Also, if the aligment would have changed the beam angle would also change, but it was still exactly at the centre of the collimating lens and even comaparing at a bigger distance it didn´t change at all.

Maybe it was just pure luck, but maybe it´s like the eplanation that came to my mind I posted above, as the glue all between the two parts is acting like a thermal isulator. Therefore the cristals are heating up much much faster, even if the whole module is heatsinked.

You know you can incrase the output by just trimming the temperature of the cristals to it´s optimum like it´s done in all the lappies. I know the KTP likes it warm but also does not like it to hot.