Washington: A new microlaser, developed at the Jozef Stefan Institute in Ljubljana, Slovenia, is the world’s first practical three-dimensional laser – cheap, portable and quick in operation with high precision output.
Matjaz Humar and Igor Musevic have developed a microdroplet 3-D laser system in which laser light shines forth in all directions from dye molecules lodged within spherical drops of helical molecules dispersed in a liquid solution.
Musevic expects that the microdroplet lasers, which can be made by the millions in seconds, will be used in making arrays of coherent light emitters.
They will be handy for a variety of imaging purposes, for example "internal-source holography."
A 3-D laser would be embedded inside the object, which is to be imaged; light coming directly from the source interferes with the light scattered by the surroundings. A three-dimensional image of the object can then be reconstructed from the interference pattern.
Instead of an expensive fabrication process, the parts of the laser assemble spontaneously through chemistry. Second, the laser can be tuned: by changing the pitch size of the helical molecules --the degree of their corkscrew thread-- the wavelength of the light can be altered.
"Scientists have been trying to make these lasers from solid state materials, but you can imagine how difficult it is to make hundreds of alternating shells of optical materials, which should be very uniform," said Musevic.
"The beauty of our approach is that such a 3-D onion droplet is self-assembled in a fraction of a second."
To tune the laser you don``t even have to replace the droplets. Their optical properties can be changed by modifying the temperature. Tuning might even be accomplished by applying an extra electric field to the drops.
The study appears in the journal Optics Express.
First Published: Thursday, December 09, 2010, 13:01