starship-design: Laser or maser?

[T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)]

Kelly replied:

>>300 and 385 kilometer diameters don't seem like a headache...
>
>A 300-400 kilometer laser array?  Again it would be a bit hard to fit on
>our moon.  Harder to sycronize since the frequencies are shorter.  Also the
>sail has now gone from a wire mesh to a reflective sheet.

Hard to fit on the moon? I don't understand, its diameter is 3476 kilometers.
The frequency is indeed increased by a factor 3, however having a solid
floor helps a lot.

I wonder are semiconductor lasers more efficient and cheaper than ordinary
lasers. What will be the costs compared to masers which cannot be made in
semiconductors?
Also on the receiving side, what are the pros and cons?
On the receiver-end we not only need a mirror, but also an absorber. Are
photocells better than skottky diodes?

Has anyone an idea where to get this kind of information?

What are the disadvantages of a reflective sheet compared to a wire mesh? Is
it only the weight?

Timothy