Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Photonics: Bright prospects

09.08.2011
A silicon chip with integrated laser and optical grating offers new possibilities for telecommunications

Silicon is an ideal platform for integrated photonic circuits because the material is cheap and readily available. Silicon chips with an integrated laser source capable of emitting light at a specific wavelength are particularly useful in telecommunications.

Unfortunately, silicon is a material with high optical loss, which often degrades the output power and performance of the laser source. Yongqiang Wei at the A*STAR Data Storage Institute and co-workers1 have now fabricated a silicon chip that integrates not only a laser, but also an optical grating that provides optical gain and ensures that the laser outputs light at wavelengths near 1,550 nm—the standard operating wavelength for telecommunications devices.

The transmission of large amounts of data through an optical fiber is based on laser beams of different wavelengths that are sent through the fiber all at the same time. For such multi-channel operation, however, the lasers need to be tuned to precise wavelengths to avoid cross-talk. This can be achieved with an optical grating.

So far, integrating a laser and an optical grating into a silicon chip has been challenging. The laser is typically made from several thin layers of different semiconductor materials, while the optical grating itself is etched out of silicon. Everything has to be precisely aligned, and the conventional way to achieve this is to grow the laser on a separate semiconductor chip. “The whole process takes more than 50 steps and requires the surface roughness of the silicon wafer to be extremely low, less than 0.3 nanometers,” says Wei.

In the new device, a light source is placed between a mirror and a curved optical grating (pictured). The grating acts like a selective mirror that only reflects light at a specific wavelength back into the laser. This creates an optical cavity that only allows lasing action at a specific wavelength, providing the precision necessary for telecommunications applications. The researchers tested their device and found that it has good performance, emitting light with optical power of 2.3 milliwatts—about the same power as a laser pointer—at a highly specific wavelength.

“The integration of multiple lasers and optical gratings on a single chip will be our next challenge,” says Wei. “Also, for practical applications, we plan to scale up our single-wavelength lasers by utilizing the same grating structure for a broader range of wavelengths in order to integrate multiple light sources on the chip.” The new device marks a major step toward the realization of commercial telecommunications devices integrated on a single silicon chip.

The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute

References
Wang, Y. et al. Silicon/III-V laser with super-compact diffraction grating for WDM applications in electronic-photonic integrated circuits. Optics Express 19, 2006–2013 (2011).

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

More articles from Information Technology:

nachricht New software speeds origami structure designs
12.10.2017 | Georgia Institute of Technology

nachricht Seeing the next dimension of computer chips
11.10.2017 | Osaka University

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>