Microelectronics has transformed how we manipulate electricity, allowing for sophisticated electronic products that are now a necessary part of our daily lives. Integrated photonics has transformed how we control light in applications such as data communications, imaging, sensing, and biomedical devices. While near-infrared lasers have made some progress, the visible-light lasers that feed photonic chips still need to be more affordable. There is a demand for chip-scale lasers that emit different colors of light.
Researchers have developed visible-light lasers with extremely pure colors ranging from near-ultraviolet to near-infrared. The lasers’ colors can be precisely tuned and extremely fast, reaching up to 267 petahertz per second. In addition, these low-cost lasers have the smallest footprint and shortest wavelength of any tunable and narrow-linewidth integrated laser emitting visible light.
Photonic integrated circuits’ coupling and propagation losses increase significantly at wavelengths shorter than red. It has hampered the development of high-performance lasers at these wavelengths. The researchers solved the coupling loss problem by using Fabry-Perot (FP) diodes as light sources, which reduces the impact of the losses on the chip-scale lasers’ performance.
The team overcame the propagation loss problem by developing a platform that minimizes material absorption and surface scattering losses for all visible wavelengths. They used silicon nitride, a dielectric widely used in the semiconductor industry, to guide the light. These visible-light lasers could be used in portable underwater ranging systems that use this technology.
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