Abstract: The invention relates to an optical sub-assembly package for use in receiver optical sub-assemblies or transmitter optical sub-assemblies in which the electrical connections between the transducer chip, e.g. photo-detector or light source, and the device printed circuit board is made by a single flexible circuit conductor extending through the wall of the package. The package is comprised of a housing and a stiffening plate, which encloses and end of the housing and forms a mechanical support for an end of the flexible circuit conductor.

Abstract: The invention relates to a receiver optical sub-assembly (ROSA) for use in an optical transceiver to convert optical signals transmitted along an optical fiber into electrical signals for use by a host device. Conventionally, light exiting the optical fiber inside an optical coupler of the ROSA encounters a refractive index mismatched interface, e.g. fiber/air, causing a portion of the light to be reflected directly back into the fiber. To minimize back reflections at the interface with the optical fiber, an optical insert is provided having an index of refraction matching that of the optical fiber, thereby moving the mismatched interface remote from the end of the fiber to an interface of the optical insert and a lens, to which the optical insert is attached.