Capillaries for fiber arrays
Fig.13 Typical example of 1x8 splitter bonded by fiber arrays
Fig.14 FTTH (Fiber To The Home)
Fiber arrays are components that connect optical waveguides and optical fibers. Conventionally, the most common type of fiber array is the V-groove type, as shown in Fig. 11. V-grooves are prepared by machining or wet etching on a glass plate that is several millimeters in thickness having a precision of ±1 μm. The optical fibers are arrayed along the grooves and fixed by an adhesive agent. The end surface is optically polished. Figure 12 shows an example of the fiber array.
There are various types of optical waveguides such as planar lightwave circuits, silicon photonic waveguides and lithium niobate waveguides. Regardless of types, channel numbers and pattern complexity of the waveguides, each waveguide must be connected to external components and devices via optical fibers.
Waveguides are prepared via techniques such as semiconductor lithography, and hence, the waveguide dimensions are controlled at submicron precision regardless of the number of waveguides (e.g., 8, 32 or 48). Therefore, the optical fibers to be attached to the waveguides also need to be arrayed at submicron precision. Fiber arrays used for such purposes are shown in Fig. 13.
Current representative optical waveguides used in conjunction with fiber arrays are 1×8 splitters for fibers to the home (FTTH) (Fig. 14) and arrayed waveguide grating (AWG) for dense wavelength divisions and multiplexing (DWDM).