Page 93 - 2020 Interconnect Innovations eBook

Another innovative method of dust-insensitive fiber optic connectivity is currently making its way into the market. This approach combines the innovations and lessons learned from previous methodologies to create a new way of addressing dust insensitivity, insertion and return loss (IL/RL) performance, repeatability, and reduced mating forces for multi-fiber array connectivity. This non-contact, total internal reflection mirror, collimation array technology combines EB connector technology and air-gap connector technology with anti-reflective coatings, offset fiber alignment, a mirror reflex collimation lens, and a springless fiber suspension mechanism to provide optimal optical alignment, enable low mating and unmating forces, support blind mating, and maintain retention strength.
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» Non-contact, total internal reflection mirror, collimation array fiber optic technology. A mirror reflex collimation lens ferrule (top left), an example of a plug and adapter interface (top center), and high-density trunk connector (top right) followed by corresponding system specifications and IL and RL measurements across all fibers in the array at both initial mating and over 100 mating cycles to illustrate change in loss.
This technology incorporates a non-traditional type of ferrule. While traditional ferrules directly align fibers to face and directly align with each other, this new technology, developed and patented by 3M, uses a mirror reflex collimation lens ferrule to first expand the light and then redirect it nearly perpendicular to the original path. The mating connector incorporates an identical assembly that, when brought together, nests within the other, completes the reversal of the light path, and re-collimates it into the receiving fiber. Though the lens ferrules make physical contact, the area where the light transitions from one to the other and the individual fibers does not. This design creates a fiber array connector that is insensitive to dust and vibration, minimizes the risk of physical damage from internal and external contact, and virtually eliminates concerns about lateral offset fiber misalignments. The result is an array connector that enables outstanding IL and RL performance and permits repeated plugging and unplugging while maintaining consistently low changes in transmittance across all fibers in both single-mode and multimode applications.
The innovative, yet extremely simple structure of this expanded beam approach opens doors for it to be used in traditional plug-adapter-plug applications, on-board optics applications, high-density trunk connectors, and blind- mating applications, the latter of which is especially important to technology advancement. Due to its low mating force and insensitivity to dust and minor lateral misalignments, this technology can be applied as a blind-mate optical backplane, midplane, and cabled backplane solution across multiple markets to address increasing data rates on the equipment chassis.
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