Photonic Arbitrary Waveform Generation Based on Delta-Sigma Modulation and Spectrum Stitching

This Letter introduces a novel approach to photonic arbitrary waveform generation (PAWG) that employs delta-sigma modulation (DSM) and spectrum stitching techniques. The approach divides a wideband target signal into multiple spectral sub-signals. Each sub-signal is processed through DSM to produce two 1-bit pulse sequences, which are modulated onto an optical pulse train using a dual-drive Mach-Zehnder modulator (DD-MZM). The DD-MZM operates differentially to double the pulse repetition rate, enhancing the bandwidth of the output waveform. After photodetection, bandpass filtering, and spectrum stitching, a wideband signal can be synthesized. A proof-of-concept experiment successfully demonstrates the generation of chirp signals with different formats, validating the effectiveness and potential of the proposed PAWG method in wideband signal generation.