Double focal switch and focal plane of cosine-squared Gaussian beams
-
1.
College of Physics Science and Engineering Technology, Yichun University, Yichun 336000, China;
-
2.
Department of Physics and Electronic Information Science, Huaihua University, Huaihua 418008, China
-
Received Date:
2007-08-09
Accepted Date:
2007-09-02
-
Abstract
In order to study the focusing properties of cosine-squared Gaussian beams(CsSGB) through a lens without aperture,the equation for the axial irradiance distribution of focused CsSGB are derived based on the Collins formula,and the analytical expression of beams waist width is presented using the second-order moment method.The double focal switch of axial intensity and the focal shift of focal plane where the real position of beams waist located are studied with numerical method.The dependence of both effects discussed above on the beams parameter b,relative incident separation s' and beams Fresnel number NF are analyzed.Results show that double focal switch can take place only for b1,and the real focal plane has a shift if s'≠1.
-
-
References
[1]
|
LÜ B D,PENG R W.Focal shift and focal switching in systems with the aperture and lens separated[J].J Optics,2002,A4(6):601-605. |
[2]
|
JI X L,LÜ B D.Focal shift and focal switch of flattened Gaussianbeams in passage through an aperture bifocal lens[J].IEEE J Q E,2003,39(1):172-178. |
[3]
|
PENG R W,LÜ B D.Focal switch of Hermite-Gaussian beams[J].Acta Physica Sinica,2003,52(11):2795-2802(in Chinese). |
[4]
|
LIU X Y,PU J X.Focal shift and focal switch of partially coherent light in dual-focus systems[J].Opt Commun,2005,252:262-267. |
[5]
|
LIU X J,LÜ B D.Focal shift in a Gaussian beams focused by a thin lens without aperture[J].Laser Journal,1997,18(3):17-22(in Chinese). |
[6]
|
JI X L,LÜ B D.Focal switch of cosine-Gaussian beams focused by a thin lens without aperture[J].Laser Technology,2005,29(6):654-656(in Chinese). |
[7]
|
KONG R X,WANG L,WANG X Q.The beam waist width and its location of the elegant cosh-squared-Gaussian beams[J].Laser Journal,2004,25(1):41-42(in Chinese). |
[8]
|
JIANG X D,WU Y M,WANG X Q.Focal plane and the position of the plane in cosine-Gaussian beams[J].Optical Technique,2006,32(3):419-421(in Chinese). |
-
-
Proportional views
-