Enhanced linear dynamic range property of Franz-Keldysh effect waveguide modulator

The spurious-free dynamic range (SFDR) of an InGaAsP-InP Franz-Keldysh effect (FKE) waveguide modulator is studied. Low-biasing the FKE modulator is shown to enhance the SFDR by 22 dB with a 3-dB optical power penalty. Polarization-independent RF operation is also obtained with low bias. At 2 mA photocurrent, the simulated narrowband and broadband SFDR are, respectively, 127 dB and 104 dB in a 1-Hz bandwidth. The measured result projects a narrowband SFDR of 129 dB-Hz/sup 4/5/ at this photocurrent.<
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