question about laser modules

I think its time I learned this basic things.
I own a 1W laser projector, for a year now.
Unlike same power laser pointer, the laser projector has a "laser module" which generates the beam. it's made of two parts, an aluminum box where the beam comes out of and another box connected to it which has a controller board in it.
What are these?
I mean a 1W laser pointer is smaller than my flashlight but this 1W laser module is several cubic centimeters.
What's the difference in the technology that requires the module to be so big if it is the same power?
I guess the board allows to turn on/off and dim the laser which is required for laser animations, but whats in the other box?

johnjack said:

Unlike same power laser pointer, the laser projector has a "laser module" which generates the beam. it's made of two parts, an aluminum box where the beam comes out of and another box connected to it which has a controller board in it. What are these?

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Your description isn't great, but I think what you are asking about is the laser head which contains the optics and diode, and the driver which may contain a DC power supply as well.

johnjack said:

I mean a 1W laser pointer is smaller than my flashlight but this 1W laser module is several cubic centimeters.
What's the difference in the technology that requires the module to be so big if it is the same power?

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Handheld lasers are not made to run continuously. Lasers inside of projectors are. The difference in size is due to different heat sinking requirements.

The difference is duty cycle. Your small hand held battery powered laser can't be turned on for long at a time because it just has a small heat sink and no active cooling, the diode would quickly overheat and burn out if left on for several minutes. A projector or also a lab laser will both need to be turned on for longer periods of time so they will need some additional cooling besides just a heat sink, such as a TEC Thermoelectric cooler (TEC or Peltier) and or a fan in addition to the heat sink.

Thanks guys.

ARG said:

Your description isn't great, but I think what you are asking about is the laser head which contains the optics and diode, and the driver which may contain a DC power supply as well.

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Sorry about that.
Something like this:


Top has the diode, lens and cooling and bottom one has the electronics.
Mine in my projector is different company but same dimensions and almost same design.

The cost increases greatly with these as the miliWatts increase (several thousand USD). Is that the cost of the better cooling mostly, or the electronics in the other box for controlling the light?

Yup, that is definitely a laser head and driver combo.
In the case of the above system it looks like it is AC powered, so it has a power supply in the electronics box as well, which accounts for majority of the bulk.

Usually the cost increases rapidly past the point where one diode won't generate the power on it's own. Once you add another diode into the system it gets much more complex requiring more optics, and more assembly time during alignment.
The cooling systems and drivers do get more complex in high end units, but it doesn't affect the price too much.

Thanks for the interesting info.

So how high mW can today's diodes produce alone? I see 10W diodes for sale for invisible light diodes, but I'm interested in the visible laser diodes (like 650nm, 532nm, 445 nm, etc) and when searching for those modules like the above one I showed get listed instead.

more optics, and more assembly time during alignment.

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Okay for first reason, I guess second won't be a cost issue for DIY build.

The cooling systems and drivers do get more complex in high end units, but it doesn't affect the price too much.

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Thanks for this info too.

So basically higher cost is due to using several diodes, optics to merge the lights from the diodes, and the cost of assemblying such setup?