Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Photonics: Double twist

09.06.2011
A silicon waveguide that converts the polarization mode of light could speed up the operation of photonic circuits

Silicon is the dominant material for the fabrication of integrated circuits and is also becoming a popular material for making photonics circuits—miniaturized circuits that use light instead of electronic signals for processing information. One of the challenges in the field, however, has been silicon’s intrinsic sensitivity to the polarization of light, which can limit the rate of information transmission. Jing Zhang, Tsung-Yang Liow and co-workers at the A*STAR Institute of Microelectronics have now developed a novel solution to this problem[1].

Light of different polarizations, which normally travel at the same speed in air, travel at different speeds in silicon waveguides due to random imperfections and asymmetries in the silicon itself. To overcome this problem, the researchers turned to a scheme known as ‘polarization diversity’, by which incoming light is split into two perpendicular modes of polarization, called the transverse electric (TE) and transverse magnetic (TM) modes. They then rotated the TM mode by 90° so that both of the modes propagate in parallel at the same speed inside the photonic circuit.

Zhang, Liow and their co-workers had previously demonstrated a silicon-based device, called a polarization rotator, which comprises the first half of the diversity scheme (see image). The rotator transforms TM light into TE light by passing the light through a horizontal waveguide and then rotating it into a vertical waveguide. In their present work, they designed, built and characterized a device that completes the second half of the scheme. Called a polarization mode converter, it transforms TE light in the vertical waveguide into TE light in a horizontal waveguide. By connecting their mode converter to their rotator, the researchers were able to construct a polarization diversity scheme that provides mode conversion to reduce propagation loss in the waveguide while retaining the original polarization state.

Both halves of the polarization rotation device work by gradually changing the geometry of the waveguide, which in turn changes the polarization mode of the light it is guiding. The Singapore research team characterized their devices by studying the signal loss introduced over the transition length between polarization modes, as well as the propagation loss in the rest of the device. They found that the device efficiencies would need to be improved to be practical, for example by reducing the roughness of the waveguide walls through thermal oxidation, and by improving the coupling between the waveguide and the fiber optic cable connected to it.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Microelectronics

Journal information

[1] Zhang, J., Liow, T.-Y., Yu, M., Lo, G.-Q. & Kwong, D.-L. Silicon waveguide based TE mode converter. Optics Express 18, 25264–25270 (2010).

Lee Swee Heng | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6333
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>