Background-Free Microwave Signal Generation Based on Unbalanced Temporal Pulse Shaping

We propose a new method to generate background-free high-frequency pulsed microwave signal based on an unbalanced temporal optical pulse shaping (TPS) system and balanced photodetection. The proposed system consists of a polarization modulator and an unbalanced TPS system realized by two conjugate dispersion elements. The carrier frequency of the pulsed microwave signal could be tuned by changing the residual dispersion of the TPS. The proposed method is theoretically analyzed and experimentally demonstrated. The experimental results show that the carrier frequency of the generated microwave pulse could be tuned over a broad frequency range. Moreover, the generated microwave pulse signal is background-free by suppressing the baseband frequency components using balanced photodetection.