Improving the optics of next-generation telecommunications

Smaller, integrated lasers can pave the way for next-generation communications and sensing technologies by introducing functionalities previously unavailable on a chip scale, including a wider tuning range and narrower laser linewidth. Malik et al. summarize recent progress on heterogenous, integrated, narrow-linewidth lasers in silicon-chip-based photonics systems.

Their work details the capabilities of several lasers to show why these lasers have attracted interest from big players in the telecommunications industry.

For example, applications requiring single-frequency energies or low noise typically require lasers with narrower linewidths. The review describes several ways of achieving this desired end with much smaller systems that do not take up much space. The authors describe how a single, powerful optical system is made by integrating multiple, chip-scale technologies on a single substrate.

“The lasers we describe operate in the O- and C-band, which form the backbone of datacenter interconnects and telecommunication networks,” co-author Aditya Malik said. “We show that heterogeneously integrated lasers are ready for field deployment, and hybrid lasers will pave the path for next generation of devices utilizing nonlinear effects.”

The integrated laser systems, which are fabricated on silicon-based waveguide circuits, can perform better than traditional laser-based electronics, Malik said.

The authors hope the electronics industry will consider integrated laser systems for a variety of applications.

“Researchers should focus on chip scale applications of integrated lasers,” Malik said. “These include optical gyroscopes, lidars, atomic sensing and fully integrated optical transceivers.”

Source: “Low noise, tunable silicon photonic lasers,” by A. Malik, C. Xiang, L. Chang, W. Jin, J. Guo, M. Tran, and J. Bowers, Applied Physics Reviews (2021). The article can be accessed at https://doi.org/10.1063/5.0046183 .