Design of a computer-generated waveguide hologram for integrated free space sensing

In this work we present a design of a computer-generated waveguide hologram coupler with an ultra-long working distance and wavelength multiplexing in the near infrared. An approximation method to compute the scalar field from a detour phase hologram is presented. The accuracy is comparable to FDTD but it is achieved much faster. Coupling efficiency from waveguide to free space and fabrication feasibility of design are optimized with the method.