How Do You Calculate the Waist Radius and Location of a Gaussian Beam?

[danifire2]

https://www.physicsforums.com/attachments/73840
This is the problem I don´t understand, I know I hace to determine the distance z1 which correspond to the widht W1, but I try to solve equation of W1 and W2 for z1 and use the fact z2 = z1 + 0.1m, but I, my question is how to determine the waist radius, because is not given and appear in all the equation I try to solve.

A Gaussian beam of wavelength λ = 10.6 μm (emitted by a CO2 laser) has widths W1 = 1.699 mm and W2 = 3.38 mm at two points separated by a distance d = 10 cm. Determine the possible locations of the waist and the waist radius.

 

[Greg Bernhardt]

Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?