A tunable optical frequency comb generator using a single dual parallel Mach–Zehnder modulator

• Flat OFC with a tunable spacing, flexible line-number and high SMSR are experimentally generated.
• Gaussian-shaped OFC is also generated with relatively lower RF power.
• The linewidth of the CW laser is taken into account. The linewidth of each mode in the comb is derived.

A scheme of generating optical frequency combs (OFC) utilizing a single dual parallel Mach–Zehnder modulator (DPMZM) is detailedly investigated. Both the theoretical analysis and experimental results show that the generator is power efficient. Gaussian-shaped OFC and flat OFC with a tunable spacing, flexible line-number and high side mode suppression ratio (SMSR) are experimentally generated with relatively lower RF power.