MARK SIEMENS - Light with a twist: an introduction to twisted light with orbital angular momentum

Mark Siemens.

University of Denver.

Jueves 20/04/2017, 14 hs.

Aula Seminario, 2do piso, Pab. I.

We normally think of light as traveling straight between points in space, but beams of light can rotate as they travel. In the simplest rotating beams, individual light particles (photons) spin as they travel and this “spin angular momentum” has been well understood for about 100 years. But less than 20 years ago, the “orbital angular momentum” form of rotation was discovered that leads to a “vortex” beam with a helical phase. These quantized vortex beams have many exciting applications, including controlling tiny micromachines, measuring star rotation, enabling super-high-resolution imaging, and allowing communication with theoretically-unlimited bandwidth.

Conventional methods for generating and measuring twisted light involved either expensive and fixed-wavelength optics or computer-controlled electro-optics such as a spatial light modulator. In this talk, I will 1.) provide a tutorial explaining the basic concepts of twisted light, 2.) discuss very simple methods for generating and measuring the orbital angular momentum of light, and 3.) highlight some exciting potential technical and scientific uses of twisted light.