Cost-effective method to mass produce quantum dot lasers unveiled

Researchers at the Electronics and Telecommunications Research Institute (ETRI) in South Korea have figured out a way to mass-produce quantum dot lasers.

Quantum dot lasers are high-precision laser devices that produce light using semiconductor particles that are only a few nanometers in size.

These particles are called quantum dots and they allow great control over the laser’s properties, making it very useful for applications that require fine-tuned light at very small scales.

For instance, quantum dot lasers can lead to high-quality optical communication devices that are used for transferring information over long distances using light. These devices are crucial for high-speed internet data transfer, smooth functioning of servers within and between data centers, and accurate medical imaging.

In their new study, ETRI researchers successfully produced and tested quantum dot laser diodes, components used in optical communication devices.

Overcoming the challenges with quantum dot laser production

The researchers wanted to produce large quantities of high-quality quantum dot laser diodes but they discovered that the conventional methods used for this purpose are slow, inefficient, require expensive indium phosphide (InP) substrate, and are therefore not scalable.

This forced them to look for alternatives and soon they came across Metal-Organic Chemical Vapor Deposition (MOCVD), a technique used for creating very thin layers (of nanoscale) of a material on a surface.

MOVCD is commonly used for research purposes. However, for the first time, the ETRI team decided to employ it to produce quantum dot laser diodes, and it worked.

“We successfully developed indium arsenide/gallium arsenide (InAs/GaAs) quantum dot laser diodes on gallium-arsenic (GaAs) substrates, which are suitable for the 1.3 µm wavelength band used in optical communications,” the study authors note .

MOCVD as a quantum dot manufacturing process delivered higher production efficiency and good uniformity, compared to conventional methods. Moreover, it used a substrate (GaAs) that is available at less than one-third the price of InP substrates.

When they tested the mass-produced quantum dot laser diodes, “The semiconductor lasers demonstrated continuous operation at temperatures up to 75 degrees Celsius, showing a world-leading achievement in the results obtained via MOCVD.”

Mass-produced quantum dot lasers have many benefits

MOCVD allowed the researchers to produce quantum dot lasers in a fast, efficient, scalable, and cost-effective manner. They claim that their approach could cut down the cost of semiconductor laser production by more than 80 percent.

This would further reduce the cost of technologies where these lasers are used. For instance, the decreased cost of quantum dot lasers will significantly bring down the price of advanced optical communication devices.

“In modern society, optical communication serves as the backbone of our industry. This study’s achievement is set to revolutionize the development of optical sources, connecting apartment complexes to large cities and undersea optical cables,” the study authors note.

However, the current research work is just a stepping stone. The researchers need to conduct more studies to further optimize and confirm the feasibility of their approach before they start using MOCVD for commercial-scale production of quantum dot lasers.

The study is published in the Journal of Alloys and Compounds .