Generalized Mach-Zehnder interferometer architectures for radio frequency translation and multiplication: suppression of unwanted harmonics by design
Résumé
A generalized array of N parallel phase modulators electrically driven with a progressive 2π/N phase shift is analyzed. For N-even, the equivalence of this configuration to parallel Mach-Zehnder architectures, and specifically the equivalence for N=4 to a dual parallel Mach-Zehnder modulator is shown. A simple approach to the design of this architecture that determines the static optical phase shifts required in each of the N parallel arms to suppress unwanted harmonics while maximizing the harmonics of interest is developed. The proposed design approach is validated by numerical simulations of N=4 and N=6 architectures with properly determined optical phase shifts. Optical single-side-band modulation (lower and upper) and frequency multiplication of an electrical drive signal with high suppression of unwanted harmonics is shown to be achievable.