Re: Is an omnidirectional laser possible?
- From: "jwill@xxxxxxxxxxxx" <jwill@xxxxxxxxxxxx>
- Date: Tue, 1 Apr 2008 00:22:28 +0000 (UTC)
It depends what you mean by a "laser". If you mean a device
with parallel-only wavefronts, then NO.
If you mean a device with coherent (phase) wavefronts, YES.
A typical laser beam manipulation is to use a diverging lens
to spread the beam beyond the diameter emitted by the laser.
This obviously still is a laser beam. Carry the manipulation
to the extreme of full-Pi divergence on a laser cavity with
two opposite emission windows, and you have something very
much the same as an omnidirectional laser.
Edward Ruden wrote:
On Mar 17, 11:37=A0pm, Igor Khavkine <igor...@xxxxxxxxx> wrote:
=2E..
Actually, no. Whatever the shape of the resonant cavity, the
monopole component of outgoing radiation must be static.
Yes, you correct, of course. Most real lasers, though, are multimode.
It is interesting to think further about whether such a mirror
arrangement would result in a multimode laser which excites several m
and n (phi and theta wave number) modes not equal to zero, but which
results in spherical convergence within the diffraction limit.
Spherical harmonics are separable in r, theta, and phi variables, so
it seems to me that spherical mirrors could still be employed.
.
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