ABSTRACT: Two vertically coupled asymmetric InGaAsP ridge waveguides were fabricated and tested as a tunable dispersion compensator. In this waveguide, two coupled modes, symmetric and antisymmetric, exist simultaneously and have a significant amount of group-velocity dispersion (GVD), making it possible to reduce the size of the dispersion compensators. Since the GVD can be continuously controlled by changing the temperature of the asymmetric coupled waveguide, a semiconductor asymmetric coupled waveguide has great potential as a basis for a compact tunable dispersion compensator. To demonstrate tunable dispersion compensation, we carried out an experiment on the pulse compression of frequency-chirped pulses by using the InGaAsP asymmetric coupled waveguide at various temperatures of the waveguide. We observed a change in the compression ratio, ranging from 42.7% to 84.2%, as the temperature of the waveguide changed from 8 to 48.9 °C. A theoretical study showed that the observed change in the compression ratio was well explained by a temperature tuning of the GVD of the coupled modes resulting from temperature-induced change in the refractive indices of the waveguide materials.
Journal of Applied Physics 12/2005; 98(11):113102-113102-6. · 2.17 Impact Factor
IEICE Electronic Express. 01/2005; 2:170-175.
IEICE Electronic Express. 01/2004; 1:193-197.