Modulation, the key to any communication system, is the adjustment of the frequency, phase, or amplitude of a carrier wave to transfer information. In a typical optical communication system, the modulation is performed through the electro-optic effect where the phase or the amplitude of light is modulated using a radio frequency (RF) signal. Integrated electro-optics exist, but they are limited by the complex integration of the material on a silicon photonics platform (e.g., lithium niobate). Material degradation, low modulation bandwidth, and the large absorption in the materials also limit the maximum modulation frequency.
Researchers at University of California, Santa Barbara have developed a novel integrated optical modulator based on the nonreciprocal phase shift in magneto-optic material. This invention can be efficiently implemented on any integrated optical waveguide, including silicon waveguides (e.g., bonding). Unlike semiconductors at RF, magneto-optic materials do not suffer from plasma free carrier absorption, and perform reliably over time. Compared to standard magneto-optic modulators, this invention does not require polarization filters, removing a difficult fabrication step in integrated optics. This technology can be effectively used as a low-loss electro-optic transducer and for sensing. The integration, broader modulation bandwidth, and low RF propagation loss can be beneficial to achieve lower power consumption compared to standard electro-optic modulators. This technology also operates over a wide temperature range that extends from room temperature to below 4 K, enabling efficient data links in large-scale systems for cryogenic supercomputing and quantum information processing.
optic, modulator, modulation, network, waveguide, RF, bandwith, data, supercomputing, quantum, sensing