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 Japanese researchers develop ultrathin, highly elastic skin display
19.02.2018 | University of Tokyo

nachricht Why bees soared and slime flopped as inspirations for systems engineering
19.02.2018 | Georgia Institute of Technology

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>