High-Power High-Order Orbital Angular Momentum (OAM) Millimeter-Wave Beams from Gyro-Devices

OAM [1] of light beams (vortex beams) was discovered earlier and has been widely employed in many applications, e.g. optical tweezers, optical drives of micro-machines, and optical communication. OAM provides an additional diversity to multiplexing techniques, which can be used in addition to conventional multiplexing methods to achieve higher data rates in wireless communication. OAM beams with different lower-order mode numbers / have been studied and used in the optical regime [2]. In the mm-wave regime, they are still under investigation, since there are difficulties associated with beam-splitting and beam­ combining processes and with the use of spiral phase plates for generation of OAM, because the wavelength is much langer than in light optics.