FEL2024 - 41st International Free Electron Laser Conference

Signal Filtering Optimization for Laser Arrival Time Measurement Based on Electro-Optic Modulator

TUP016-THA

20 Aug 2024, 16:20

4h 40m

POLIN

Board: TUP016-THA

Student Poster Presentation Electron diagnostics, timing, synchronization & controls Poster session

Speaker

Bowei Wu (Shanghai Advanced Research Institute)

Description

The LAM system in XFELs is crucial for measuring and compensating for time jitter in laser transmission. The EOM encodes phase information onto the reference pulse amplitude, but amplitude noise can affect measurement accuracy. In this study, we analyzed the spectral characteristics of the optical pulse signal output from the EOM using FFT, identifying primary noise sources. We then compared pulse amplitude stability under different cutoff frequencies to find an optimal filtering scheme. Experimental results showed that at a 3000 MHz cutoff frequency, the pulse amplitude maintained good stability (CV = 0.007) without significant signal distortion. This finding suggests an effective approach to suppress amplitude noise in LAM systems.