Researchers demonstrate the ability to multiplex and transfer data between twisted beams of light with different amounts of orbital angular momentum — a development that provides new opportunities for increasing the data capacity of free-space optical communications links.

/pdf/terabit-free-space-data-transmission-employing-orbital-47zsgn5cdx.pdf

Terabit free-space data transmission employing orbital angular momentum multiplexing

The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

Materials research plays a vital role in transforming breakthrough scientific ideas into next-generation technology. Similar to the way silicon revolutionized the microelectronics industry, the proper materials can greatly impact the field of plasmonics and metamaterials. Currently, research in plasmonics and metamaterials lacks good material building blocks in order to realize useful devices. Such devices suffer from many drawbacks arising from the undesirable properties of their material building blocks, especially metals. There are many materials, other than conventional metallic components such as gold and silver, that exhibit metallic properties and provide advantages in device performance, design flexibility, fabrication, integration, and tunability. This review explores different material classes for plasmonic and metamaterial applications, such as conventional semiconductors, transparent conducting oxides, perovskite oxides, metal nitrides, silicides, germanides, and 2D materials such as graphene. This review provides a summary of the recent developments in the search for better plasmonic materials and an outlook of further research directions.

/pdf/alternative-plasmonic-materials-beyond-gold-and-silver-1p8fd7ol50.pdf

Alternative Plasmonic Materials: Beyond Gold and Silver

The series of precisely spaced, sharp spectral lines that form an optical frequency comb is enabling unprecedented measurement capabilities and new applications in a wide range of topics that include precision spectroscopy, atomic clocks, ultracold gases, and molecular fingerprinting. A new optical frequency comb generation principle has emerged that uses parametric frequency conversion in high resonance quality factor (Q) microresonators. This approach provides access to high repetition rates in the range of 10 to 1000 gigahertz through compact, chip-scale integration, permitting an increased number of comb applications, such as in astronomy, microwave photonics, or telecommunications. We review this emerging area and discuss opportunities that it presents for novel technologies as well as for fundamental science.

http://science.sciencemag.org/content/sci/332/6029/555.full.pdf

Microresonator-Based Optical Frequency Combs

Temporal dissipative solitons are observed in a nonlinear, high-finesse, optical microresonator driven by a continuous-wave laser. This approach enables ultrashort pulses to be generated in spectral regimes lacking broadband laser gain media and saturable absorbers, making it potentially useful for applications in broadband spectroscopy, telecommunications, astronomy and low-phase-noise microwave generation.

Temporal solitons in optical microresonators

Raised-cosine instead of rectangular windowing of OFDM symbols provides a steeper spectral roll-off. After dispersion-compensated transmission, inverse windowing at the receiver maintains orthogonality. Therefore, multiple OFDM bands even with few subcarriers can be efficiently multiplexed.

Raised-Cosine OFDM for Enhanced Out-of-Band Suppression at Low Subcarrier Counts

Traceable Power Measurement of LTE Signals; 17th International Congress of Metrology

A plasmonic dual-drive transmitter with co-designed driver electronics featuring 120 GBd on-off keying, with a single ended drive voltage of 450 mV and BER performance of 5.7 × 10−7 is demonstrated in a 500 m direct detection transmission scheme.

Dual-Drive Plasmonic Transmitter with Co-Designed Driver Electronics operated at 120 GBd On-Off Keying

We investigate the applicability of nm-thin dielectric layers—as often used in macroscopic devices—to increase nanoscale-device nonlinearities. We show that modulator performances can be improved by a factor >2, compared to low-index dielectrics.

Dielectric Layers in Plasmonic-Organic Hybrid Modulators

We demonstrate a 70 Gbit/s photonic wireless link on a single carrier at 60 GHz using a single polarization. To our knowledge, this is the highest data rate on a single polarization 60 GHz carrier.

Juerg Leuthold

Papers

Raised-Cosine OFDM for Enhanced Out-of-Band Suppression at Low Subcarrier Counts

Traceable Power Measurement of LTE Signals; 17th International Congress of Metrology

Dual-Drive Plasmonic Transmitter with Co-Designed Driver Electronics operated at 120 GBd On-Off Keying

Dielectric Layers in Plasmonic-Organic Hybrid Modulators

70 Gbit/s photonic wireless link at 60 GHz