Manufacturing equipment to convert laser light into frequency signals

Researchers working at Purdue University, USA, National Institute of Standards and Technology (NIST), have created a device small enough to mount on computer chips, which can help convert Continuous laser light into many ultra-short radio frequency signals. This device can be integrated in sensors, communication systems and laboratory instruments.

The results of this study were published online in Nature Photonics , published in October 2011.

These ultra-short radio frequency signals are spread at very high rates, corresponding to hundreds of billions of signals in a second, according to Andrew Weiner, Professor of Electrical and Computer Engineering, Purdue University, United States. States

The device is called: "Microring resonator box" made of silicon nitride, which is compatible with silicon materials widely used in electronic devices. The laser's infrared light enters the IC through a single fiber optic cable and is guided by a waveguide inside the "microring resonator box".

These ultra-short radio frequency signals consist of multiple segments corresponding to different frequencies, called "frequency combs."

By precisely controlling this "frequency comb," the researchers hope to create: advanced optical sensors that detect and measure: dangerous materials or pollutants; Ultra-sensitive spectral detection for the laboratory to research and develop communication systems (based on optics), to transmit large amounts of information with better quality when increasing bandwidth.

It is also the technology platform for developing a generation of broadband electrical signals with feasible applications in the areas of wireless communication and radar systems.

"Light originates from a continuous laser, also called a single-frequency laser. The intensity of this laser is constant, not a super-short radio frequency signal," Weiner said. But when passing through the "microring resonator" this light is transformed into "frequency comb" that includes multiple frequencies at equal distances. Use a range of adjustable "microring resonators" for different frequency filtering to create a variety of ultra-short radio frequency signals. Another advantage of the "microring resonator box" is the tiny size.

Laser light undergoes a "non-linear interaction" situation when passing through i, which will create a 'frequency comb' of the newly transmitted frequencies from the device by another fiber optic cable.

"Non-linear interactions are very important for generations of" frequency combs " , according to Fellow Fellow Fahmida Ferdous. With non-linear interactions, we obtain a "frequency comb" of many frequencies, including those generated at the beginning and the rest are newly created frequencies. "Microring resonator box".

Although other researchers have previously demonstrated the usefulness of generation technology -
"frequency comb" . However, this is the first time, researchers have been processing frequencies using "arbitrary optical waveform technology ," which pioneered researchers at Purdue University, China. United, led by Weiner. Researchers were able to control the amplitude and state of each spectrum line, knowing that there were two types of "frequency combs": "total coherence" and "partial coherence" , opening up new paths. to study physical processes.