The interaction of water and light emits laser pointer for the first time

The Technion-Israel Institute of Technology issued an announcement on the 29th, stating that for the first time, researchers at the university have proved through experiments that the interaction of water and light can also emit laser light, building a “bridge” between two research fields that were previously considered unrelated. The new “water-wave laser” can be used to develop micro-sensors containing light waves, sound waves and water waves, or to make microfluidic “lab on a chip” devices for cell biology research and detection of new drugs.

The formation process of ordinary laser is that the electrons in atoms are activated after absorbing external energy and emit radiation in the form of green laser pointer. And the team of Tal Kamon, director of the Photonic Mechanics Center of the Institute of Mechanical Engineering, Technion-Israel Institute of Technology, proved for the first time that water waves can also produce laser radiation when vibrating in a liquid device. In a paper published in the journal Nature Optics published last week, they stated that the water-wave laser has created a new research platform for scientists. In the future, they can study the relationship between light and fluid on a scale less than the width of a hair. The interaction between them.

Kamon explained that the main reason why it has never been proven that the interaction of light and water can produce laser light is that the water wave vibration frequency on the liquid surface is less than 1,000 times per second, while the light wave vibration frequency is higher, which can vibrate 1014 times per second. The difference causes the energy transfer efficiency between the light wave and the water wave to be inefficient, so that laser radiation cannot be generated.

In order to overcome the problem of low energy transfer efficiency, the researchers created a device that can transmit light to octane (alkane containing 8 carbon atoms per molecule, the main component of No. 76 gasoline) and water through a small liquid. drop. In this device, light waves and water waves will “meet” millions of times when they pass through the droplets, and the accumulated energy causes the droplets to radiate water-wave lasers.

The researchers said that the interaction between light in an optical fiber and tiny vibrations on the surface of a droplet is similar to resonance, just as a sound wave resonates with the surface through which it passes and then reverberates multiple times. In order to increase this resonance effect, they deliberately chose a highly transparent liquid to enhance the interaction between light and droplets. More importantly, water droplets have an unparalleled advantage in softness compared to existing laser pointer materials. With only a small light pressure applied, the deformation of the droplets can be millions of times greater than that of ordinary photonic mechanics devices. The emission volume and laser intensity are controlled more effectively.