Modulation measurements on active optoelectronic devices

A travelling flux model of an AIOW (active integrated optic waveguide) has been presented from which the main modulation characteristics of the guide have been obtained. It is seen that light at wavelengths close to the lasing wavelength require marginally more current to achieve transparency, but the optical input-output nonlinearity is worse. The active guide is shown to cause some harmonic and intermodulation distortion as well as pulse distortion. At relatively high powers of typically 1 mW, the harmonic distortion is about -20 dB but for 100 μW this improves to almost -30 dB. The corresponding experimental measurements have been found to be in good qualitative agreement with the theoretical results. For a mean output power of typically 100 μW the harmonic distortion is typically -30 dB at low modulation indices rising to -20 dB at m=0.47. The measured spectra of the detected signal is also in good agreement with the computed spectra