Creating Airy Beams Using Simple Optical Elements

Jonathan Gill, Martin G. Cohen and John Noé

Laser Teaching Center
Department of Physics and Astronomy
Stony Brook University

Airy beams are non-diffracting optical beams first predicted by Berry and Balazs in 1979 and first demonstrated experimentally by Siviloglou, Broky, Dogariu, and Christodoulides in 2007. The wavefronts of such beams exhibit a cubic phase variation. What makes an Airy beam unique is that it can be created in one dimension and that its lobe of highest intensity propagates along a parabolic path. Airy beams can be used for a variety of purposes including particle guidance, remote sensing and plasma channel generation. Airy beams are typically generated using specialized optical devices such as spatial light modulators (SLMs) or cubic phase masks. Besides cost, both of these specialized methods have limitations: an SLM cannot be used with a high-power laser, and a cubic phase mask is not tunable. An alternative method which is both simple and inexpensive and also not subject to these limitations is to exploit aberrations created by ordinary lenses to create the required cubic phase modulation of the wavefront (Papazoglou, Suntsov, Abdollahpour, and Tzortzakisin, Physical Review A, 2010).

In this project, we used the method of Papazoglou et al to create a high-quality Airy beam. The setup included a 635 nm fiber-coupled diode laser and negative and positive 80 mm FL cylindrical lenses. Tilting and displacing the negative lens creates a coma aberration (cubic phase modulation); the subsequent positive lens removes aberrations other than coma and roughly collimates the beam. The resulting wavefronts were imaged with a 200 mm cylindrical Fourier transform lens into a Thorlabs DCC1545M CMOS camera and analyzed with ImageJ software. The transverse deflection of the highest-intensity lobe of the beam was observed by moving the camera along a linear rail to positions within a few cm of the Fourier focal plane. The graph below shows the recorded deflection of the Airy beam (points) along with a prediction (line) derived from the measured width of the lobe of highest intensity at the focal plane. The slight linear discrepancy between data and prediction is due to a small misalignment between the path of the beam and the camera rail.

This work is supported by the Simons Foundation and the Laser Teaching Center.