Dynamic-Range Enhancement and Linearization in Electrooptically Modulated Coherent Optical Links

We present a general analysis of various electrooptic-modulation configurations on the system performance of a coherent analog optical link. We evaluate the dependence of the modulation scheme of the optical modulator and its properties on the system dynamic range and linearity. Linearization of a coherent optical link based on extending the length of a directional-coupler modulator is also described, illustrating the unique considerations when linearizing a coherent link. System-level modeling of an analog coherent optical link under different modulation configurations is presented.