Technology.am (Apr. 15, 2009) — Scientists have demonstrated, for the first time, lasers in which the direction of oscillation of the emitted radiation, known as polarization, can be designed and controlled at will.
This innovation opens the door to a wide range of applications in photonics and communications, and it represents an important new step towards beam engineering of lasers with unprecedented flexibility, tailored for specific applications,” explains a scientist at the Harvard School of Engineering and Applied Sciences.
The novelty of their approach is that instead of being conducted externally, which requires bulky and expensive optical components, manipulation of the beam polarization is achieved by directly integrating the polarizer on the laser facet. This compact solution is applicable to semiconductor lasers and other solid-state lasers, all the way from communication wavelengths to the mid-infrared and Terahertz spectrum”.
Light sources with a desirable polarization state are useful for a wide variety of applications.
The researchers sculpted a metallic structure, dubbed a plasmonic polarizer directly on the facet of a quantum cascade (QC) laser to get the results. The QC laser emitted at a wavelength of ten microns. The team was able to control the state of polarization by generating both linearly polarized light along an arbitrary direction and circularly polarized light.