30 January 2004 San Jose, CA Lightwave -- Arrayed Fiberoptics Corp. has introduced an epoxy-free fiber array designed to be used as a subcomponent for planar lightwave circuits (PLCs), such as arrayed waveguide gratings (AWGs).
Currently, the industrial practice for PLC waveguide-to-fiber coupling is simple butt-coupling using epoxy. In this approach, the PLC edges are polished, aligned, and epoxy bonded to a fiber array device. The fiber array device is typically made by machining V-grooves into the surface of a glass or silicon plate, and placing the fibers in these grooves. Epoxy bonding is proven to provide quick and simple alignment, low cost, and robust packaging.
However, this approach leaves epoxy in the optical path, says Arrayed Fiberoptics, where it causes limitations in power, performance, and reliability due to epoxy degradation. These problems are most acute for AWGs because they are typically used in long-haul DWDM applications, which require very high power.
These limitations have inspired various attempts to eliminate epoxy from the optical path, typically through the use of additional hardware such as microlenses or external mounting plates. However, due to the complexity and cost of these approaches, they have not been widely adopted.
Arrayed Fiberoptics' epoxy-free fiber arrays (EFFAs) incorporate a patent-pending, integrated epoxy-blocking structure. These EFFAs preserve the simplicity, low cost, and robustness of typical fiber butt-coupling, while keeping the optical path epoxy-free, the company claims. As a result, PLC manufacturers can use their existing packaging designs with very little modification. Arrayed Fiberoptics says the EFFAs offer an unprecedented combination of power handling, performance, price, miniaturization, and reliability. They can be configured in linear arrays up to 1x64 channels and 2-D arrays, with array pitch as small as 127 microns. Even in large arrays, EFFAs provide very precise positioning of fibers, to +/- 0.3 microns in both the horizontal and vertical dimensions. This is much higher precision than is available from the V-groove technology traditionally used for similar applications, the company asserts. Further, unlike V-grooves, these EFFAs enable not only linear arrays, but also 2-D arrays.
Typical applications for the EFFAs include coupling to PLCs or array devices, such as AWGs, beam splitters, optical add/drop multiplexers, optical crossconnect switches, microlens arrays, etc. Arrayed Fiberoptics will team with component vendors to integrate these EFFAs into their existing devices for improved characteristics. Alternatively the arrays can be used to create new component designs.
Evaluation samples of Arrayed Fiberoptics' EFFAs are available now with 250-micron pitch; EFFAs with pitch as small as 127 microns are currently in development. The company will demonstrate sample devices at the Optical Fiber Communication (OFC) conference in Los Angeles, February 24 - 26, 2004.