As deployment of fiber to the home (FTTH) within multiple dwelling units (MDUs) is growing, more technicians will be
involved in the deployment of optical drop cables, and there is a desire to use craft and practice similar to what is used
for copper cables. We introduce a solid bend insensitive fiber in this application that is backwards compatible to G.652D
fiber, and has macrobending, splice loss and system performance to meet the very demanding conditions of these
applications. A closer look at the demands of this environment has made it necessary to re-evaluate reliability in these
critical applications. We apply the Power Law Model to predict reliability in these demanding applications, and provide
experimental evaluation of the model through testing on optical fibers and cables. It will be shown that bends and tension
need to be considered together when evaluating the reliability of the passive optical plant.
We report thorough investigations of photonic crystal waveguide properties in the slow light regime. The transmission and the group index near the cutoff wavelengths oscillate in phase in close analogy with the 1D photonic crystal behavior. The influence of having a finite number of periods in the photonic crystal waveguide is addressed to explain the spiky character of both the transmission and group index spectra. The profile of the slow-light modes is stretched out into the first and second rows of the holes closest to the waveguide channel. One of our strategies to ameliorate the design of photonic crystal devices is to engineer the radii of holes in these rows. A topology optimization approach is also utilized to make further improvements. The results of the numerical simulations and the optical characterization of fabricated devices such as straight waveguides with bends and couplers are presented. A nice match is found between theory and experiment.
Very low propagation losses in straight planar photonic crystal waveguides have previously been reported. A next natural step is to add functionality to the photonic crystal waveguides and create ultra compact optical components. We have designed and fabricated such structures in a silicon-on-insulator material. The photonic crystal is defined by holes with diameter 250 nm arranged in a triangular lattice having lattice constant 400 nm. Leaving out single rows of holes creates the planar photonic crystal waveguides. Different types of couplers and splitters, as well as 60, 90 and 120 degree bends have been realized. We have designed and fabricated components displaying more than 200 nm of useful bandwidth around 1550 nm. Design strategies to enhance the performance include systematic variation of design parameters using finite-difference time-domain simulations and inverse design methods such as topology optimization. We have also investigated a new device concept for coarse wavelength division de-multiplexing based on planar photonic crystal waveguides. The filtering of the wavelength channels has been realized by shifting the cut-off frequency of the fundamental photonic band gap mode in consecutive sections of the waveguide. Preliminary investigations show that this concept allows coarse de-multiplexing to take place, but that optimization is required in order to reduce cross talk between adjacent channels and to increase the overall transmission. In this work the design, fabrication and performance of these planar photonic crystal waveguide components are reviewed and discussed.
We report on direct numerical calculations and experimental measurements of the group-index dispersion in a photonic crystal waveguide fabricated in silicon-on-insulator material. The photonic crystal is defined by a triangular arrangement of holes and the waveguide is carved out by introducing a one-row line defect. Both the numerical and experimental methods are based on the time of flight approach for an optical pulse. An increase of the group index by approximately 45 times (from 4 to 155) has been observed when approaching the cutoff of the fundamental photonic bandgap mode. Numerical 2D and 3D simulations of pulse dynamics in the waveguide made by the time-domain method shows excellent agreement with measured data in most of the band. These group index values in a photonic crystal waveguide are to the best of our knowledge the largest numbers reported so far by direct tracking of pulse propagation.