Beam diameter

[Adrian Hill]

Is the beam diameter or a laser poportional to the laser power or is it simply a function of the focusing optics?

[Scott Shepherd]

The optics.

[Neal Schlee]

Is the beam diameter or a laser poportional to the laser power or is it simply a function of the focusing optics?

The Mode of the raw beam is also important.

Neal

[Scott Challoner]

Although power doesn't affect beam diameter, beam diameter can affect power if I'm correct. I'm pretty sure my salesman told me that if you switch from a lens that provides a .005" diameter spot size to a lens that provides a .010" spot size, you will halve your power. Not entirely sure that's how it works, but that's what I've been told.

[Adrian Hill]

But what about the diameter of a laser as used in a dvd writer - surely there is more to it than mode and optics. What about light frequency?

[Rodne Gold]

The laser depends on energy density , the smaller the focussed beam (which will depend on the raw beam diameter. lens etc) the more energy it can pack into the spot and the more effective it will be . it still has the same power but more of it per sq mm.

[Dan Hintz]

Is the beam diameter or a laser poportional to the laser power or is it simply a function of the focusing optics?
Your question is ambiguous, hence the differing answers.

The beam diameter coming out of the cartridge is, for the most part, a function of the hole size in the partial-transmittance optic (i.e, the beam end). While cartridge power has an effect on how large of a hole you want to use, there's no direct link between one or the other. The beam quality mentioned earlier (denoted 'M' in the literature) describes the power distribution over the cross-section of the beam.

The final beam diameter, the focused portion is a function of the focusing optic, as well as the beam diameter of the incoming beam. The laser's wavelength sets the lower theoretical limit on the smallest focal size.

[Pete Bejmuk]

The High-Def optics that ULS has requires a special lens (?) right outside the beam window to widen the beam to eventually give it more power when it focuses, if I remember correctly.

I know that occasionally "problematic" tubes can have more than one beam right out of the window, "sattelites" so to speak. If you put a large cube of plexi near the window and fire it hot, instead of a just single burn hole you get one or two additional tiny ones alongside the main beam.