Most of the lasers used in items such as DVD players or optical mice are inorganic. They last much longer than organic lasers (which utilize carbon-based materials to amplify light), but they're also comparatively expensive and complex to make, plus their range of wavelengths is limited. Developing more durable organic lasers would be one way of addressing the situation, but a European research team has come up with another – just make them really cheap and easily-replaceable.
Using an inkjet printer and a commercial ink mixed with dye, the scientists printed square pixels onto a quartz slide. Because inkjet printers can print so precisely into one tiny area, the slide didn't need to be masked off, and there was very little wastage of the ink/dye mix.
That slide is known as a "lasing capsule," and each of the pixels on it act as a gain medium when placed in an organic laser – the gain medium is what amplifies the light, and is also what typically degrades too quickly in regular organic lasers. While this particular type of gain medium isn't longer-lasting than others, the capsule that it's printed on can simply be pulled out from the rest of the laser and replaced as needed. It's likened to changing the blades in a razor.
The scientists believe that once production is ramped up, such lasing capsules could be manufactured for just a few cents each. Changing the color of the laser is as simple as using different colors of dyes. Ultimately, it is hoped that the technology could be used for sending data over short plastic fibers, and as a tool for analyzing chemical or biological samples.
The research was conducted by scientists from the University of Paris 13 and Ecole Nationale Supérieure des Mines de Saint Etienne in France, and SEMILAB in Hungary. It is described in a paper that was recently published in the Journal of Applied Physics.
Source: American Institute of Physics