Nanowerk  November 24, 2021 Today, most frequency shifters are either too inefficient, losing a lot of light in the conversion process, or they can’t convert light in the gigahertz range. A team of researchers in the US (Harvard University, Caltech, industry) etched coupled ring-resonators and waveguides on thin-film lithium niobate. In the first device, two coupled resonators form a figure eight-like structure. Input light travels from the waveguide entering as one color and emerging as another. It provides frequency shifts as high as 28 gigahertz with about 90% efficiency. It can be reconfigured as tunable frequency-domain beam splitters. The second device […]