An optical system comprising: a base having a fiber retention and alignment section and an optical coupling section, the fiber retention and alignment section including a recess that extends between spaced apart lateral sidewalls and has a plurality of alignment members, each alignment member being configured to receive an optical fiber therein, the optical coupling section having an optical coupling block and including a plurality of optical coupling elements, each optical coupling element having an ellipsoidal reflecting surface defining a first focal point and a second focal point, a first focal surface being generally aligned with the first focal point, a second focal surface being generally aligned with the second focal point, the first focal surface and the second focal surface being spaced apart and at an angle to each other, wherein the angle of the first focal surface relative to the second focal surface is between approximately 70 and 110 degrees and an optical path extending through each optical coupling element from the first focal point to the reflecting surface and to the second focal point, each alignment member being aligned with the first focal point of one of the optical coupling elements, wherein the optical coupling section includes a surface with a recess therein, the recess defining at least a portion of each of the reflecting surfaces; a plurality of optical fibers, each optical fiber being positioned within one of the plurality of the alignment members and adjacent one of the first focal surfaces; and a plurality of optical components, each optical component being positioned adjacent one of the second focal surfaces, characterized in that the optical coupling block is formed of a polymer material, the polymer of the optical coupling block has a first coefficient of thermal expansion, and further includes an expansion restricting component secured to the optical coupling section, the expansion restricting component being formed of material having a second coefficient of thermal expansion, the first coefficient of thermal expansion being greater than the second coefficient of thermal expansion, wherein the expansion restricting component is a reflector cover secured to the optical coupling section to seal the recess, and wherein a fiber retention cover is configured to limit lateral or transverse thermal expansion of the recess of the fiber retention and alignment section. a base having a fiber retention and alignment section and an optical coupling section, the fiber retention and alignment section including a recess that extends between spaced apart lateral sidewalls and has a plurality of alignment members, each alignment member being configured to receive an optical fiber therein, the optical coupling section having an optical coupling block and including a plurality of optical coupling elements, each optical coupling element having an ellipsoidal reflecting surface defining a first focal point and a second focal point, a first focal surface being generally aligned with the first focal point, a second focal surface being generally aligned with the second focal point, the first focal surface and the second focal surface being spaced apart and at an angle to each other, wherein the angle of the first focal surface relative to the second focal surface is between approximately 70 and 110 degrees and an optical path extending through each optical coupling element from the first focal point to the reflecting surface and to the second focal point, each alignment member being aligned with the first focal point of one of the optical coupling elements, wherein the optical coupling section includes a surface with a recess therein, the recess defining at least a portion of each of the reflecting surfaces; a plurality of optical fibers, each optical fiber being positioned within one of the plurality of the alignment members and adjacent one of the first focal surfaces; and a plurality of optical components, each optical component being positioned adjacent one of the second focal surfaces, characterized in that the optical coupling block is formed of a polymer material, the polymer of the optical coupling block has a first coefficient of thermal expansion, and further includes an expansion restricting component secured to the optical coupling section, the expansion restricting component being formed of material having a second coefficient of thermal expansion, the first coefficient of thermal expansion being greater than the second coefficient of thermal expansion, wherein the expansion restricting component is a reflector cover secured to the optical coupling section to seal the recess, and wherein a fiber retention cover is configured to limit lateral or transverse thermal expansion of the recess of the fiber retention and alignment section.