The inventive configurable
optical fiber polarization mode coupler is capable of providing a low-loss, high-
coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-
channel spacing, and an optical device having a plurality of closely-spaced
waveguide interfaces with a second channel-to-
channel spacing, where each end of the
optical fiber coupler array is configurable to have different channel-to-
channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing, and that are preferably optimized for use with photonic integrated circuits, such as
coupling to dense optical input / output interfaces,
wafer-level testing, etc. The novel
optical coupler array includes a plurality of waveguides (at least one of which may optionally be polarization maintaining), that comprises at least one gradually reduced vanishing core
fiber, at least in part embedded within a common housing structure. Advantageously, at least one embodiment of the present invention comprises a physically untappable secure
optical fiber link component comprising at least one optical
fiber polarization mode coupler configured as a
pitch reducing optical
fiber array (PROFA) interconnect.