Scientists in Slovenia have developed a microlaser that is said to be the world's practical, three-dimensional laser. Detailed in an Optics Info Base report (PDF), the device is made of self-assembled cholesteric liquid-crystal microdroplets. In it, laser light is emitted in all directions from dye molecules lodged within spherical drops of helical molecules dispersed in a liquid.
The creators, Matjaž Humar and Igor Muševič, say millions of the devices can be made in seconds. They can be used to make arrays of coherent light emitters, usable in various imaging purposes. One such application is internal-source holography, wherein a 3D laser would be embedded inside the object.
The cholesteric liquid crystals are similar to those that make up the basis for LCDs. Because they don't mix well with the surrounding polymer liquid, the index of refraction varies outwards. As such, the laser components are self-assembled by way of their chemical properties and how they combine.
They can also be tuned by changing the pitch size of the helical molecules, which affects the wavelength of light. This can be done simply by modifying their temperature by applying an electric field.
There is no indication of when the invention will see a commercial application.