Linearity of double heterostructure electroabsorptive waveguide modulators

The linearity of electrooptical waveguide modulators based on the Franz-Keldysh effect with respect to the voltage-transmission characteristic has been investigated experimentally and theoretically. For a GaAs-AlGaAs double heterostructure modulator the values of the signal-to-noise ratio due to anharmonic and intermodulation distortion have been found to be small enough to suffice the requirements for analog optical transmission in multichannel broad-band fiber network systems compatible to existent cable networks. The results are also applicable to materials in the bandgap region of the optimum fiber transmission wavelengths around 1.3 /spl mu/m and 1.5 /spl mu/m. The advantages in comparison with directly modulated semiconductor lasers will be discussed.<
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