Optical connection carries data via orbital angular momentum

Dec. 4, 2012
Researchers at Tsinghua University believe they have come up with a practical way to use optical beams that carry orbital angular momentum (OAM) to increase the data-carrying capacity of wireless optical interconnects.

Researchers at Tsinghua University (Beijing, China) believe they have come up with a practical way to use optical beams that carry orbital angular momentum (OAM) to increase the data-carrying capacity of wireless optical interconnects. Beams with OAM carry quanta of angular momentum that, for a certain frequency, can be encoded on the beam by electro-optic tuning of the mode order in a ring cavity at that frequency. Decoding is done using gratings and Mach-Zehnder interferometers.

The ring cavity, which is fabricated on an integrated-optics chip, has, in addition to the ring, a bus waveguide and eight download waveguides (each including an arc-shaped section next to the ring and a grating near the ring’s center). Light from the ring is coupled into the download waveguides and is emitted by the eight gratings to form a free-space beam with OAM. At the other end, quaternary (rather than octenary) decoding is done to allow for beam degradation. The decoding is accomplished (on another integrated-optics chip) by coupling the free-space light into waveguides using gratings, and then coherently superposing the results to recover the signal either using an interferometer or arrayed-waveguide gratings. The OAM device could also be used to create vortex beams. Contact Xue Feng at[email protected].

Sponsored Recommendations

March 31, 2025
Enhance your remote sensing capabilities with Chroma's precision-engineered optical filters, designed for applications such as environmental monitoring, geospatial mapping, and...
March 31, 2025
Designed for compatibility with a wide range of systems, Chroma's UV filters are engineered to feature high transmission, superior out-of-band blocking, steep edge transitions...
March 31, 2025
Discover strategies to balance component performance and system design, reducing development time and costs while maximizing efficiency.
March 31, 2025
Explore the essential role of optical filters in enhancing Raman spectroscopy measurements including the various filter types and their applications in improving signal-to-noise...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!