Rotationally symmetric construction optics for a waveguide focusing grating

Waveguide grating couplers have been under study as a method of focusing laser diode radiation on the surface of an optical data storage device. In this letter, we describe a simple method of holographically constructing a waveguide grating coupler at visible wavelengths which may be used with collimated infrared laser radiation to form high numerical aperture, diffraction limited beams. The design method includes the necessary compensation aberrations to offset the effects of differences between construction and end-use wavelengths.