Can you focus a laser pointer until it is strong enough to cut?

There are good chances. Not for other materials though.To be fear, not at the conditions a pointer system can achieve. The energy involved is too low to satisfy the needs of most materials you may be interested in to obtain a "cut".

Gh writing speed DVD and Microscribe enabled drives have much more power (up to 100mW and more). With these can be achieved something but real a cut. Focussing as you have in mind is not the correct task to get it right.

A laser diode produces primary and secondary rays. What is really needed to cut is the energy of the primary emission. Secondary emissions mostly degrade the overall efficiency if added to the primary emission due to the typical effect of signal reduction due to phase differences.

Optical focussing, as meant in your question, exactly does displace the phases of the secondary emissions and sums all this rays on a single spot causing the mentioned degradation. That means the cutting ability also depends on the quality of the laser. If it produces much secondary emissions, the primary emission's "power" may be too poor to produce sufficient fluence to achieve a cut.

Laser pointers use laser diodes of very poor quality as much energy is lost in secondary emissions. Please remember that laser light is very dangerous. Either CD/DVD laser diode's rays, else occasional, as direct or first reflection observation permanently damages the eye's retina.

There is no way to recover from such an injury!

I do not see how. An ordinary laser pointer does not have the proper beam to do this. Even shining it through a magnifying glass would probably not bring about your desired result.

But try it and see. It sounds like something that would be on the show Mythbusters.

There's just not enough power in those. Laser pointer diodes generally put out a few milliwatts. You can overdrive them, but they'll burn out quickly even at 1/10th watt.

You need at least a 1 watt laser to do any sort of cutting. To cut, the thing needs to reach its melting point, which can only be achieved if you can pump power onto it faster than it can radiate it out or conduct it away. The thermal conductivity of aluminum, for example, is 250 W/m-C.To get the heat a mere 1 millimeter away, for a heat input of 300C (not even close to melting it), you'd need 750 watts.

In other words, you'd need a fair bit of wattage to get it to cutting, over an area much smaller than 1 millimeter. Aluminum is actually the worst case; you'd have better luck with a less conductive material like plastic or paper. But clearly, amounts of energy in the 5 mW range just aren't going to (ahem) cut it.

Perfect a bluetooth keyboard pointer for my micro projector equipped phone. Meetings anywhere anytime, as long as there are outlets nearby to charge up.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.