We utilize the anomalous dispersion of planar photonic crystals near the dielectric band edge to control the wave- length-dependent propagation of light. We typically observe an angular swing of up to 10° as the input wavelength is changed from 1290 nm to 1310 nm, which signifies an angular dispersion of 0.5°/nm (“Superprism” phenomenon). Such a strong angular dis- persion is of the order required for WDM systems. By tuning the incident angle, light beams with up to 20° divergence were collimated over a 25 nm (1285 nm to 1310 nm) bandwidth using a triangular lattice (“Supercollimator” phenomenon). The wavelength collimating range can be extended from 25 nm to 40 nm by changing the lattice from triangular to square. These two devices can be realized in the same configuration, simply by tuning the wavelength. Sources of loss are discussed.
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