Published online by Cambridge University Press: 01 February 2002
Self-focusing is one of the key issues in laser plasma physics applications. Problems involving a multidimensional beam within an inhomogeneous plasma are diffficult to handle. This paper presents the investigation of two-dimensional self-focusing of a laser beam in a plasma whose density n(r, z) is a function of radial as well as z coordinates. The nonlinear mechanism responsible for modification of the background density and the dielectric function is of ponderomotive type. A variational technique is used here for deriving the equations for the beam width and the longitudinal phase. It is observed numerically that an initially diffracting beam is accompanied by oscillatory self-focusing of the beam with distance of propagation. The effect of inhomogeneity scale lengths is also observed. The increase in Lr (= L∥/L⊥) results in oscillatory self-focusing and defocusing with distance of propagation. Furthermore, critical fields for self-trapping of a laser beam as a function of refraction, diffraction lengths and scale lengths of inhomogeneities are also evaluated. Lastly, whatever parameters are chosen, the phase is always negative.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.