An optical coupling device for the efficient transfer of an optical signal between optical components. The device can receive an optical signal from a transmitting component connected to its input end and efficiently transmit that signal to a receiving component connected to its output end. The instant device includes a combination of two or more dielectric materials and provides impedance matching at the input and output ends as well as impedance conservation during propagation of the optical signal through the device. Impedance matching at the input and output ends is controlled through variations in the relative proportions of the constituent dielectric materials of the device in the cross-sections of input and output ends to achieve an effective permittivity that closely matches that of the interconnected component. Impedance conservation within the instant device is achieved through simultaneous variations in the cross-sectional shape of the device and cross-sectional fill factors of the constituent dielectric materials. The impedance conditions, in combination with high spatial overlap at the input and output ends, minimize losses in the power of signal transmitted between the interconnected optical components.