Optical coupling system for use in an optical communications module, an optical communications module that incorporates the optical coupling system, and a method

An optical receiver (Rx) module comprising:

• an optical Rx portion, the optical Rx portion including at least a first light detector for converting light received thereby into an electrical signal and a first optical element for optically coupling light onto the first light detector;
• an optical coupling system, the optical coupling system being positioned to receive a first light beam passing out of an end of a first optical fiber coupled to a first optical port of the optical RX module, wherein the first light beam propagates along a first optical pathway of the optical coupling system, the optical coupling system including at least a first reflective and focusing (RAF) lens receives the first light beam propagating along the first optical pathway and reflects the received first light beam toward the first optical element of the optical Rx portion and focuses the reflected first light beam onto the first optical element of the optical Rx portion;
• and
• a refractive index-matching material disposed in between, and in contact with, the first optical port and the first end of the first optical fiber such that no air gaps exist in between the first optical port and the first end of the first optical fiber.

A method for optically coupling light output from a first end of a first optical fiber onto a light detector of an optical receiver (Rx) portion of an optical Rx module, the first end of the first optical fiber being mechanically coupled with a first optical port of the optical Rx module, wherein the optical coupling system is formed in a piece of material that is transparent to a wavelength of the received light beam, the method comprising:

• with a first reflecting and focusing (RAF) lens of an optical coupling system of the optical Rx module, receiving a light beam passing out of the first end of the first optical fiber and propagating along a first optical pathway that extends from the first end of the first optical fiber to the first RAF lens;
• with the first RAF lens, reflecting and focusing the received light beam onto a first optical element disposed in the optical Rx portion of the optical Rx module;
• and
• with the first optical element of the optical Rx portion, optically coupling the light beam focused thereon onto a first light detector of the optical Rx portion, wherein the piece of material in which the optical coupling system is formed is devoid of air gaps at least along the first optical pathway of the optical coupling system, and wherein a refractive index-matching material is disposed in between, and in contact with, the first optical port and the first end of the first optical fiber such that no air gaps exist in between the first optical port and the first end of the first optical fiber.