Re: ATM Non lasing lerer diode Question

["Arjan te Marvelde (ELN)" <Arjan.te.Marvelde@eln.ericsson.se>]

Nils Olof, Peter,

About the aperture of a solid state laser, have you thought of this:

The divergence of a light beam with a gaussian intensity distribution is given by:

	theta = lambda / pi * waist

where the waist is the 1/e diameter of the light distribution at the aperture (flat wavefronts) and theta is the divergence angle at large distance.

Since you probably see no diffraction rings in the spot produced on the wall, the profile can be approximated well enough by a gaussian distribution. Also the x and y directions may be superimposed since they are orthogonal. 
Therefore if you measure the divergence angle of the beam, you can deduce its waist, or the approximate aperture dimensions.

An example laser gives a beam of 7.5 x 30 deg, indicating a waist of approximately 1.3 x 0.35 um.

Hope this helps (and is correct too ;o)

/AtM