6. Conclusion

In this article, we have described the steps involved in the complete integration of a Mach-Zehnder optical interferometer for amplitude modulation in a lithium niobate crystal, using optical waveguide technologies based on metal diffusion or proton exchange. The performance achieved today, whether in terms of control voltages, optical losses, modulation bandwidths, or extinction ratios, meets all user requirements and needs in a wide range of applications and wavelength ranges, from visible to mid-infrared, for telecommunications, sensors, instrumentation, LIDARS, complex laser systems, quantum technologies, and communications.

We also discussed the case of the dual parallel Mach-Zehnder interferometer I&Q modulator for modulating both amplitude and phase in digital QPSK systems, illustrated by the example of analog CS-SSB modulation for optical carrier frequency...