Misalignment-tolerant total-internal-reflection fiber optic interface modules and assemblies with high coupling efficiency

摘要

Fiber optic interface modules and assemblies using same are disclosed, wherein the modules and assemblies are tolerant to misalignment and have a high coupling efficiency. The module has at least one lens that defines a folded optical path through the module body. The folded optical path is formed by total internal reflection within the module body from an angled wall of the module. The lens has an aspheric front surface and a planar rear surface and is configured to have an optimum tolerance to a lateral misalignment relative to a light source while maintaining a high coupling efficiency between the light source and an optical fiber.

主权项

1. A fiber optic interface module configured to provide optical communication of infrared light between a light source and an optical fiber having an end and a core, comprising:
a module body that is substantially transparent to light having an infrared wavelength and that includes a top surface and a bottom surface, wherein the top surface defines a total-internal-reflection (TIR) mirror, an end wall, and optical fiber support feature that supports the optical fiber with the optical fiber end abutting the end wall, wherein the optical fiber support feature is a groove; a lens surface formed on the bottom surface of the module body and constitutes the only surface having optical power, wherein the lens surface, the TIR mirror, the end wall and an intervening portion of the module body define a lens having a folded optical axis comprising a source optical path OPs between the lens surface and the TIR mirror; and the lens surface having a shape that provides a theoretical coupling efficiency CE≧85% between the light source and the optical fiber and that defines a back focus that falls within the optical fiber core at a back focus distance F2 from the end of the optical fiber when the core of the optical fiber is operably supported in the optical fiber support feature such that the source optical path OPs can be laterally offset from a light-source axis of the light source by a lateral misalignment δZ.