Innovations in Silicon Photonics

Frost & Sullivan predicts that silicon photonics (SiP) devices can boost data transfer speed to more than 100 gigabytes per second—orders of magnitude higher than what is available currently. SiP sensors have the potential to revolutionize medical diagnosis and, by extension, the healthcare industry itself. Read more about companies working in this space.

Silicon photonics (SiP) refers to the use of advanced optical systems for the transmission of data, using light as the transmission medium. According to Intel, a pioneer of this technology and one of its most enthusiastic patrons, SiP brings together “two of the most important innovations” that have defined the electronics revolution of the last century: silicon integrated circuits and semiconductor laser. Frost & Sullivan, in its study of this emerging technology, defines SiP as the “integration of both optical and electronic components in the same chip, in order to generate, detect, process, and modulate light to transmit data.” SiP finds tremendous acceptance in the telecommunications, information technology, consumer electronics, aerospace and defense, and health care industries.

Silicon exhibits non-linear optical properties, which is fundamental in the interaction of light with light. SiP devices are compatible with conventional complementary metal-oxide-semiconductor (CMOS) sensors, which make them conducive to ultra-small transceivers, and also address the problem of bandwidth. It is estimated that by integrating silicon chips with optical fibers, as many as 40 channels can be created using a single strand of fiber. Each of these channels can carry light at a different wavelength, greatly expanding transmission bandwidth. Frost & Sullivan predicts that SiP devices can boost data transfer speed to more than 100 gigabytes per second—orders of magnitude higher than what is available currently.

The telecommunications industry is experiencing a 30% year-on-year growth rate, largely propelled by the demand for basic connectivity in emerging countries. There is also a parallel demand for faster and higher bandwidth data transfer. As 5G networks come into commercial play, SiP can satisfy this demand, and minimize loss: it has been observed that the loss during data transfer using an optical medium is only 0.2 decibel per kilometer—far less than conventional electrical cables.

SiP sensors have the potential to revolutionize medical diagnosis and, by extension, the healthcare industry itself. Silicon nanophotonics find application in point-of-care testing, enabling high-speed kits for home and laboratory settings. The size, speed, versatility and accuracy of these kits in testing a variety of analytes can be greatly enhanced by using SiP-based biosensors.

A number of semiconductor companies, research labs, and electronics corporations are pumping hundreds of millions of dollars into the development and commercialization of this rather nascent technology. In 2016, President Obama announced the launch of the ambitious Cancer Moonshot 2020 (now referred to as Cancer Breakthroughs 2020), a multi-center initiative to drive research to develop more accurate diagnostic devices and efficient therapies. One of the core technology partners in this initiative is the National Photonics Initiative (NPI), a scientific community that brings together hospitals, companies and research organizations. The NPI is deeply involved in supporting research at the interface of photonics, optics and electronics (photonic integrated circuits or PIC) to improve the diagnostic confidence of medical imaging and screening modalities.

PIC in Medical Diagnostics

The Photonics Device Group at the Politecnico di Milano (Milan, Italy), in collaboration with the European Defense Agency, is using photonic chips to fabricate next-generation biosensors. The group is focused on creating a suite of photonic circuits on a single chip to facilitate a high throughput and multi-sensory “lab-on-a-chip” platform that will be able to detect a variety of analytes, each in the nano- or pico- scale. There is also an effort underway to develop PIC-based DNA sensors to identify genetic mutations, which will help in the early detection of cancer.

Finisar Corp. (Sunnyvale, Calif.) has developed a suite of photo-detectors that operate at the C-band, supporting signal detection of up to 160 Gbaud. Finisar’s BPDV4121 offers long-distance signal detection operating at an extremely low power of 3 volts and high bandwidth of 100 GHz, and achieving data transmission speeds of 100 gigabytes per second. This is currently the fastest photodetector to be commercialized, and is being used for optical tests and measurements.

Optical Transceiver Chips for Healthcare Data Transfer

As described earlier, photonic systems form the core of high-speed and high-volume data transfer. A commonly-quoted statistic says that global digital health data will reach 25 exabytes (1018 bytes) by 2020. A large proportion of this data will be imaging data generated in imaging centers, laboratories and hospitals. High-speed transfer of such data to enable collaboration among stakeholders requires a sturdy transmission channel.

Sicoya  (Berlin, Germany) offers  optical  transceiver  chips  for  data  center  interconnects  used  in  servers.  It offers an advanced fabrication technique for high-speed circuits that uses silicon-germanium (SiGe) dual transistors in the traditional CMOS process for high frequency and low noise. Sicoya is targeting the high-speed data centers market, developing devices that offer speeds up to 100 gigabytes per second.

The Road Ahead

The Cancer Breakthroughs initiative, the BRAIN Initiative (funded by the U.S. National Institutes of Health), the European Union-funded Human Brain Project, and many other ambitious projects are expected to generate large volumes of data. Simultaneously, there is also a large and ever-increasing quantum of data being generated by everyday operations in health care facilities, with emphasis on data security and privacy. This calls for a secure and robust information technology infrastructure to be integrated into the health care ecosystem. Silicon photonics has fast emerged as the next-generation technology addressing the need for faster data transmission in different industries.