Coupler technology advancessilicon photonics

Coupler technology advancessilicon photonics

A patented fiber technology dubbed Helic TC by its creator, in-fiber photonics developer Chiral Photonics (Pine Brook, NJ), promises to more efficiently bridge the gap between fiber-optic applications built around high refractive index contrast structures and those based on low-index-contrast fiber. The company believes this development will be especially useful in silicon photonics applications — which many consider to be the future of computing.

High-index-contrast structures within photonic integrated circuits (PICs) or planar lightwave circuits (PLCs) form the basis for a large fraction of the recent worldwide innovation in integrated optics. Via highly efficient lasers, extremely sensitive sensors, and waveguides moving vast amounts of data through small radius bends, these faster, smaller, and power-conserving PICs and PLCs promise to advance everything from consumer electronics to personal computing. PICs and PLCs stand to bring more sensitive and less invasive biomedical diagnostics, feed ever more information to wireless devices, and refine industrial processes from drug development to navigation systems.

“We believe this is a significant enabling technology for planar nanophotonics and in the field of high index contrast photonics more generally,” said Victor Kopp, director of R&D. “In addition, to the endface and evanescent coupling devices we are currently supplying, we plan to use this technology to introduce a passive alignment solution for board-to-board and chip-to-chip interconnects.”

The tapered coupler technology device comprises two concentric cores and a cladding. While the two cores have low index contrast, the outer core and the cladding have high contrast.

At input, the low-contrast cores facilitate low-loss connectivity to standard fibers. The fiber then tapers down over its length, eliminating the inner core by the output end. At the output, high index contrast enables low-loss connectivity to high index contrast structures such as planar waveguides.

The interconnect exploits a dual-core fiber design to allow light from a conventional low-aperture fiber to be efficiently endface-coupled into another waveguide with smaller mode field dimensions and higher numerical aperture. This permits index-matching compounds to be used between the coupler and waveguide, eliminating the need for microlens-based coupling and air gaps. The technology supports both polarizing and polarization maintaining coupler variations.

For more information, go to http://www.chiralphotonics.com, or call Gary Weiner at 973-732-0030, ext. 114, or e-mail gweiner@chiralphotonics.com.

Ralph Raiola