Researchers at the University of California, Davis, have developed a chirped grating emitter with ultra-sharp instantaneous field of view (IFOV) for optical beam-steering applications.
Optical phased arrays (OPAs) are attractive due to their numerous optical beam-steering applications including: free-space optical interconnect, sensing, data communication and light detection and ranging. Current OPAs, however, lack efficient transfer of energy and a uniform direction and mode of light travel (emission/coupling and propagation) that is required for the longer wavelengths of light used in such beam-steering applications. One way to reduce the surface emission rate is to employ shallow etch depths on silicon but the fabrication of gratings is very difficult.
Researchers at the University of California, Davis, have developed a silicon based OPA platform for far-field pattern beam-steering applications. The platform produces an ultra-sharp IFOV and a uniform emission intensity profile up to 8 mm in length. The platform has been successfully tested to be able to modulate emission rates for a combination of duty cycles with custom grating widths while maintaining a clear far field pattern and uniform power emission over 1 mm length. By integrating silicon with lower refractive index silicon nitride (Si3N4), silicon-dioxide (SiO2) and blazed grating fabrication techniques, the platform produces a narrow beam that does not introduce side lobes and can be used to filter emissions from undesired polarization rotations for top emission efficiency.
|United States Of America||Issued Patent||10,429,588||10/01/2019||2017-566|
grating emitter, silicon, silicon nitride, silicon dioxide, optics, field of view, optical phased arrays, wavevector, surface emission, beam-steering, power, energy, tiling, multi-tiling, Si3N4, SiO2, Si, OPA, IFOV