First laser light interaction between water and light

Israel Institute of Technology announced on the 29th that the researchers of the university for the first time demonstrated through experimentation that the interaction between water and light can also emit laser light, building a “bridge” between the two research areas that were previously considered to be unrelated. The new "water-wave laser" can be used to develop miniature sensors containing light, acoustic and water waves, or to create microfluidic "chip lab" devices for cell biology research and detection of new drugs.

The formation of a common laser is that electrons in the atom absorb external energy and are activated to emit radiation in the form of a laser. The team of Tal Carmon, director of the Institute of Photon Mechanics at the Institute of Mechanical Engineering of the Israel Institute of Technology, demonstrated for the first time that water waves can also generate laser radiation when they vibrate within a liquid device. In a paper published in the journal Nature and Optics published last week, they said that water-wave lasers have created a new research platform for scientists and they can study light and fluid in less than one hair-width scale. Interactions.

Carmen explained that the main reason why it had never been demonstrated before that light interacts with water to generate laser light is that the frequency of the water wave on the liquid surface is less than 1000 times per second, and the frequency of the light wave vibration is higher. It can vibrate 1014 times per second. Frequency 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.

To overcome the problem of low energy transfer efficiency, the researchers created a device that can transmit light through optical fibers to octane (alkanes containing 8 carbon atoms per molecule, main ingredient of 76# gasoline) and microscopic liquids formed by water. drop. In this device, light waves and water waves meet millions of times when they pass through the droplets, and the accumulated energy lets the droplets radiate out of the water-wave laser.

The researchers stated that the interaction between the light in the fiber and the micro-vibration on the surface of the droplet resembles resonance, just as the sound wave emits multiple echoes after resonating with the surface it passes through. In order to increase this resonance effect, they deliberately chose highly transparent liquids to enhance the interaction between light and droplets. More importantly, water droplets have unparalleled advantages over existing laser materials in terms of softness. By applying a small light pressure, the degree of droplet deformation can be millions of times larger than that of ordinary photonic mechanical devices, and therefore it can be applied to lasers. Emissions and laser intensity are more effectively controlled. (Reporter Nie Cuirong)