Phys.org  October 5, 2021 A random laser has many degrees of freedom that are not available in conventional cavity lasers. Based on this discovery, an international team of researchers (Israel, France) showed that laser emission can be simply controlled by shaping the pump profile that provides the gain inside the scattering medium. This is done optically with total flexibility. They found that selective excitation significantly reduces the lasing threshold, while lasing efficiency is greatly improved. Their spatial locations are critical to boost laser power efficiency. By efficiently suppressing the spatial hole burning effect, they could turn on the optimally outcoupled random […]