The world's smallest blue light laser

Russian scientists have successfully developed the world's smallest blue nanolaser, with a volume of only 0.005 cubic micrometers, breaking through the diffraction limit theory that the size of the light source must not be smaller than its wavelength. This breakthrough has opened up a new technological path for the development of cutting-edge fields such as ultra high definition displays, quantum processors, AR systems, and microsensors.

The world's smallest laser

ITMO University scientists, together with colleagues from the Center for Photonics and Two-Dimensional Materials at MIPT, have developed the world's smallest blue-emitting laser. The discovery makes it possible to create ultra-sharp displays with a resolution previously considered unattainable even in theory. The nanolaser can also be used in augmented reality devices, quantum processors, and compact sensors.

— The volume of the created nanolaser is only 0.005 microns, which is about 13 times smaller than the cube of the wavelength of its radiation. This is a record high for the blue range (400-500 nm). The active element of the laser is a microscopic cube of perovskite grown by chemical synthesis in solution. Its dimensions are about 195 × 190 × 145 nm. The particle is placed on a silver substrate, which plays the role of a mirror that holds and amplifies light inside the nanoparticle," explained Denis Baranov, one of the authors of the work, a leading researcher and head of the laboratory at the Center for Photonics and Two—Dimensional Materials at MIPT.

The co—author of the work is Denis Baranov, a leading researcher and head of the laboratory at the Center for Photonics and Two-Dimensional Materials at MIPT.

Scientists have managed to overcome the diffraction limit, a fundamental principle according to which it is impossible to create a light element smaller than the wavelength of the emitted light. The new laser uses a unique mechanism based on polaritons, hybrids of light and matter. Unlike traditional lasers, it does not need to overcome a high threshold barrier to start generation.

— The mechanism of operation of the device is based on the advanced concept of polariton lasers. There is a strong connection between excitons (combining the properties of light and matter particles) and the light localized inside the nanoparticle. This makes it possible to achieve generation without the population inversion threshold (the content of a large number of particles. — Ed.), which reduces energy consumption and simplifies the design. The combination of the strong exciton response of perovskite, its high crystal quality and optimized resonant properties makes our nanolaser design the best available in the blue spectral range," explained the scientist.

Currently, laser operation has been demonstrated at low temperatures (about 80 K, or -193 °C). The next task of the scientists will be to achieve room temperature generation, which is necessary for the commercial application of the technology.

The basis for new technologies
— Our laboratory has been working on the creation of nano- and microlasers for more than seven years, but the developed technology for creating such compact nanolasers in the blue region of the spectrum is unique. We have succeeded in synthesizing nanolasers in the form of a colloidal solution of nanoparticles in a liquid, which allows them to be deposited on any surface. This will make it possible to integrate them with active arrays for displays, photonic integrated circuits, and even use them for bioimaging tasks," said Sergey Makarov, professor at the ITMO University Faculty of Physics and head of the Laboratory of Hybrid Nanophotonics and Optoelectronics.

The development of a new radiation source will help in forming the element base for modern photonics, especially in terms of overcoming the diffraction limit, which for decades has been a "brick wall" in the way of laser miniaturization, especially in the blue part of the spectrum, added Roman Ponomarev, NTI expert, head of the Laboratory of Integrated Photonics at PSNIU.

"Creating a nanolaser that is not only shorter than the wavelength of light, but also works stably in the blue range is a breakthrough in the field of photonics and nanotechnology. This proves that we have learned how to control light on such a small scale, which was previously considered unattainable," the expert believes.

Pavel Gostischev, a leading researcher at the Laboratory of Advanced Solar Energy at NUST MISIS, agrees with this assessment of the development. In his opinion, the main advantage of the technology can be considered the simplicity of production operations, which will significantly accelerate the path from scientific research to finished products.

The development of perovskite-based quantum dot technology and the use of this material as ultra-compact lasers can really significantly advance developments in the field of next-generation displays, optical chips and biomedical sensors, Pavel Gostischev said.

Source:IZ.RU