A smart optical chip to improve telecommunications

From the internet to fiber or satellite communications and medical diagnostics, our daily lives rely on optical technologies. These technologies use pulsed optical sources to transfer, retrieve or calculate information. The mastery of optical pulse shapes thus opens the way to new advances.

Doctoral student Bennet Fischer and postdoctoral researcher Mario Chemnitz, in the team of Professor Roberto Morandotti of the National Institute for Scientific Research (INRS), have developed an intelligent pulse shaper integrated on a chip. The device’s output can autonomously adjust to a user-defined target waveform with surprisingly low technical and computational requirements.

An innovative design

Ideally, an optical waveform generator should autonomously produce a target waveform for convenience, minimize experimental requirements to drive the system and read the waveform, to facilitate online monitoring. It must also exhibit long-term reliability, low losses, fiber connectivity and maximum functionality.

Among other things, practical imperfections, such as the fidelity of individual devices, deteriorate the accessible performances compared to those initially designed or simulated. “We find that evolutionary optimization can help overcome the inherent design limitations of systems-on-chips and thus raise their performance and reconfigurability to a new level,” says the postdoctoral researcher.

Machine learning for smart photonics

The team was able to realize this device alongside the recent emergence of machine learning concepts in photonics, which promise unprecedented system capabilities and performance. “The optical community is eager to learn more about new methods and implementations of smart devices. In our work, we present an interconnected set of methods enabling machine learning of great relevance, both for optical communities technical than academic.”

The researchers used evolutionary optimization algorithms as a key tool to repurpose a programmable photonic chip beyond its original use. Evolutionary algorithms are computer programs inspired by nature, which make it possible to efficiently optimize multi-parameter systems with significantly reduced computational resources.

This innovative research was published in the journal Optical. “For us, young researchers, doctoral students and post-docs, it is essential for our careers that our research is visible and shared. Thus, we are truly grateful and overwhelmed to learn that our work is published in such an exceptional and interdisciplinary journal. “It warms our ambitions to continue our work and seek even better implementations and breakthrough applications. It supports our efforts and it’s just a great honor,” says Mario Chemnitz.

The team’s next steps include investigating more complex chip designs. The objective is to improve the performance of the device, as well as the on-chip integration of the optical sampling (detection scheme). Eventually, they could provide a single, compact, plug-and-play device.

Source of the story:

Material provided by National Institute for Scientific Research – INRS. Original written by Audrey-Maude Vézina. Note: Content may be edited for style and length.