In response to the optical packaging needs of a rapidly growing silicon photonics market, Chiral Photonics, Inc. (CPI)
has developed a new generation of ultra-dense-channel, bi-directional, all-optical, input/output (I/O) couplers that bridge
the data transport gap between standard optical fibers and photonic integrated circuits. These couplers, called Pitch
Reducing Optical Fiber Arrays (PROFAs), provide a means to simultaneously match both the mode field and channel
spacing (i.e. pitch) between an optical fiber array and a photonic integrated circuit (PIC). Both primary methods for
optically interfacing with PICs, via vertical grating couplers (VGCs) and edge couplers, can be addressed with PROFAs.
PROFAs bring the signal-carrying cores, either multimode or singlemode, of many optical fibers into close proximity
within an all-glass device that can provide low loss coupling to on-chip components, including waveguides, gratings,
detectors and emitters. Two-dimensional (2D) PROFAs offer more than an order of magnitude enhancement in channel
density compared to conventional one-dimensional (1D) fiber arrays. PROFAs can also be used with low vertical profile
solutions that simplify optoelectronic packaging while reducing PIC I/O real estate usage requirements.
PROFA technology is based on a scalable production process for microforming glass preform assemblies as they are
pulled through a small oven. An innovative fiber design, called the “vanishing core,” enables tailoring the mode field
along the length of the PROFA to meet the coupling needs of disparate waveguide technologies, such as fiber and onchip.
Examples of single- and multi-channel couplers fabricated using this technology will be presented.