Determination of angular momentum content in partially coherent beams through cross correlation measurements

A means to measure orbital angular momentum in a partially coherent beam is demonstrated by using a wavefront folding interferometer. This interferometer allows us to study the cross correlation function of a partially coherent vortex beam. It is shown that the cross correlation function possesses ring dislocations which are related to the topological charge of the partially coherent vortex, exhibiting a one to one correspondence between the number of rings and the value of the topological charge, thus providing a direct measure of the orbital angular momentum.

[1]  Matthew E. Anderson,et al.  Measuring vortex charge with a triangular aperture , 2011, CLEO 2011.

[2]  Kishan Dholakia,et al.  Measuring the orbital angular momentum of partially coherent optical vortices through singularities in their cross-spectral density functions. , 2012, Optics letters.

[3]  David M. Palacios,et al.  Spatial correlation vortices in partially coherent light: Theory , 2004 .

[4]  A S Marathay,et al.  Spatial correlation singularity of a vortex field. , 2004, Physical review letters.

[5]  G. Swartzlander,et al.  Pinched optical-vortex soliton , 2001 .

[6]  K. T. Gahagan,et al.  Optical vortex trapping of particles , 1996, Summaries of papers presented at the Conference on Lasers and Electro-Optics.

[7]  Grover A Swartzlander,et al.  Optical rankine vortex and anomalous circulation of light. , 2007, Physical review letters.

[8]  Grover A. Swartzlander,et al.  Propagation dynamics of optical vortices , 1997 .

[9]  Yangjian Cai,et al.  Effect of spatial coherence on determining the topological charge of a vortex beam , 2012 .

[10]  J. P. Woerdman,et al.  Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes. , 1992, Physical review. A, Atomic, molecular, and optical physics.

[11]  D. Palacios.  An Optical Vortex Coherence Filter , 2004 .

[12]  Yujing Han,et al.  Measuring the topological charge of optical vortices with an axicon. , 2011, Optics letters.

[13]  Y. Kivshar,et al.  Generation of white-light optical vortices through cascaded four-wave mixing , 2011, 2011 International Quantum Electronics Conference (IQEC) and Conference on Lasers and Electro-Optics (CLEO) Pacific Rim incorporating the Australasian Conference on Optics, Lasers and Spectroscopy and the Australian Conference on Optical Fibre Technology.

[14]  C. A. Hill,et al.  Optical helices and spiral interference fringes , 1994 .

[15]  Ignacio Hernández Aranda,et al.  Propagation of Electromagnetic Helmholtz-Gauss Beams Through Paraxial Optical Systems and Spatial Correlation Vortices , 2008 .

[16]  M. Beijersbergen,et al.  Method for probing the orbital angular momentum of optical vortices in electromagnetic waves from astronomical objects. , 2008, Physical review letters.

[17]  R R Alfano,et al.  Double-slit interference with Laguerre-Gaussian beams. , 2006, Optics letters.