Phys.org June 29, 2021
An international team of researchers (USA – Harvard University, Italy) has developed a tunable laser that has two components—a laser diode and a reflective metasurface. The metasurface surface uses supercells, groups of pillars which work together to control different aspects of light. It is designed so that only the selected wavelength has the correct direction to enter back in the diode enabling the laser to operate only at that specific wavelength. The wavelength can be changed by moving the metasurface with respect to the laser diode. The shape of the laser beam can be fully controlled to project a complex hologram and has the ability to split the incident light into three independent beams, each with different properties. According to the researchers these abilities will enable many applications from scientific instrumentation to augmented or virtual reality and holography…read more. Open Access TECHNICAL ARTICLE
The incident light can be split into three independent beams, each with different properties — a conventional beam (right), a Bessel beam (center) and an optical vortex (left). Credit: Christina Spägele/Harvard SEAS