Separation of radiation and absorption losses in two-dimensional photonic crystal single defect cavities

We have characterized the optical modes present in a two-dimensional photonic crystal single defect cavity fabricated in an InP/In0.53Ga0.47As/InP double heterostructure thin film on a glass slide. The cavity resonance was tuned to different frequencies in the 1.55 μm spectral region. Radiation losses and material absorption influence the measured value of cavity quality factor Q. We separated these two loss mechanisms by performing a curve fit of the loss rate 1/Q versus the wavelength-dependent absorption coefficient of In0.53Ga0.47As. By extrapolating this curve to zero absorption, the radiation loss rate 1/Qrad is obtained.