Image: Size comparison of the new mTP laser array (Photo courtesy of Rockley)
Scientists have developed what is believed to be the world’s first micro-transfer-printed (mTP) silicon-photonics-based laser for commercial applications. This groundbreaking achievement by Rockley Photonics Holdings Limited (Oxford, UK) is expected to allow the company to further increase the density and reduce the size of its high-density spectrophotometer chips – which are already the world’s smallest for broadband infrared wavelength laser spectrometry (covering 1000 nanometers of spectrum) and are smaller in area than LED-based solutions currently used in wearables. New silicon-photonics-based biosensing chips using mTP technology are expected to be available in the first half of 2024. This advancement could potentially have a significant impact across a wide range of applications, including the design of exceptionally small wearable devices for the detection and measurement of multiple biomarkers.
With this breakthrough in the mTP of silicon-photonics-based lasers, Rockley has dramatically increased the laser density of its photonics integrated circuits (PICs) for biosensing, creating what it believes to be the world’s highest-density broad-wavelength laser spectrophotometer chip, surpassing its own previous achievements. Moreover, the mTP process is expected to reduce manufacturing costs and enable thinner, smaller footprint and higher-density chip designs. These attributes are powerful benefits for use in consumer and medtech devices and could facilitate the integration of Rockley’s biosensing technology into future tiny wearables. Leveraging the mTP process, the new PIC technology will integrate a laser-generating “membrane” with a thickness of only 4 microns. The potential applications for this higher-density and smaller-footprint chip technology extend beyond biosensing and health monitoring into other areas, such as ultra-small wearables, clothing, or XR/VR/AR headsets and glasses.
“Applying the micro-transfer printing process to the production of integrated lasers is a huge breakthrough that we believe will have a tremendous impact on wearable biosensing and on the photonics industry as a whole,” said Dr. Andrew Rickman, chairman and chief executive officer of Rockley. “We arguably have some of the most sophisticated photonics technology in the world, and this unprecedented level of miniaturization raises the bar even further. By creating biosensing chips that are smaller, lower-cost, and more efficient, we can continually improve our wearable biosensing products and deliver novel, relevant, and more powerful ways to monitor our health.”
Rockley Photonics Holdings Limited