Abstract

A novel compact broadband single-mode coupler is proposed. It can provide highly efficient coupling from a cw laser diode (LD) located in close proximity (and parallel) to the waveguide. It consists of a microprism and two perpendicular volume holographic gratings. Because of the specific geometry, the gratings offer opposite-sign wavelength dispersions with two independent degrees of freedom. Thus, the coupling wavelength curve can be adjusted to the waveguide modal curve with high (second-order) accuracy. As a result, the waveguide coupling is highly efficient within a broad range of LD wavelength shifts (10-100) nm). The presented prism-grating hybrid coupling system can be used in 3-D photonic processors which are based on single-mode waveguide optical horizontal and vertical communication paths. It will provide chip to chip interconnections.

© 1991 Optical Society of America