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Phoenix666 writes:

For the first time, researchers have built a nanolaser that uses only a single molecular layer, placed on a thin silicon beam, which operates at room temperature. The new device, developed by a team of researchers from Arizona State University and Tsinghua University, Beijing, China, could potentially be used to send information between different points on a single computer chip. The lasers also may be useful for other sensing applications in a compact, integrated format.

[...] The joint ASU-Tsinghua research team used a monolayer of molybdenum ditelluride integrated with a silicon nanobeam cavity for their device. By combining molybdenum ditelluride with silicon, which is the bedrock in semiconductor manufacturing and one of the best waveguide materials, the researchers were able to achieve lasing action without cooling, Ning said.

A laser needs two key pieces – a gain medium that produces and amplifies photons, and a cavity that confines or traps photons. While such materials choices are easy for large lasers, they become more difficult at nanometer scales for nanolasers. Nanolasers are smaller than 100th of the thickness of the human hair and are expected to play important roles in future computer chips and a variety of light detection and sensing devices.

The choice of two-dimensional materials and the silicon waveguide enabled the researchers to achieve room temperature operation. Excitons in molybdenum telluride emit in a wavelength that is transparent to silicon, making silicon possible as a waveguide or cavity material. Precise fabrication of the nanobeam cavity with an array of holes etched and the integration of two-dimensional monolayer materials was also key to the project. Excitons in such monolayer materials are 100 times stronger than those in conventional semiconductors, allowing efficient light emission at room temperature.

Practical photonics comes one step closer.

Original Submission