Generalized Mach–Zehnder interferometer architectures for radio frequency translation and multiplication: Suppression of unwanted harmonics by design

• A design approach for suppression of unwanted harmonics in parallel phase modulators is proposed.2πN phase shift.
• Circuit architecture comprises N-parallel phase modulators driven with progressive phase shifts.
• Analysis for frequency translation and multiplication is demonstrated by numerical simulations.

A generalized array of N   parallel phase modulators electrically driven with a progressive 2π/N2π/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.