Photodetection-induced relative timing jitter in synchronized time-lens source for coherent Raman scattering microscopy

Jiaqi Wang,Ping Qiu

doi:10.1142/s1793545817430039

Abstract

Synchronized time-lens source is a novel method to generate synchronized optical pulses to mode-locked lasers, and has found widespread applications in coherent Raman scattering microscopy. Relative timing jitter between the mode-locked laser and the synchronized time-lens source is a key parameter for evaluating the synchronization performance of such synchronized laser systems. However, the origins of the relative timing jitter in such systems are not fully determined, which in turn prevents the experimental efforts to optimize the synchronization performance. Here, we demonstrate, through theoretical modeling and numerical simulation, that the photodetection could be one physical origin of the relative timing jitter. Comparison with relative timing jitter due to the intrinsic timing jitter of the mode-locked laser is also demonstrated, revealing different qualitative and quantitative behaviors. Based on the nature of this photodetection-induced timing jitter, we further propose several strategies to reduce the relative timing jitter. Our theoretical results will provide guidelines for optimizing synchronization performance in experiments.

Highlights

Two-color synchronized ultrashort laser source is needed for a variety of physical, chemical and biomedical applications, such as pump-probe experiment[1] and nonlinear optical microscopy.[2,3] Tightly synchronized mode-locked laser[4] and synchronized pumped optical parametric oscillators[5] are commonly used for imaging purposes
The relative timing jitter, dened as the peak position di®erence between the two pulse trains, arises. Here we identify another origin of relative timing jitter in the synchronized time-lens source system-electrical timing jitter introduced by photodetection
The relative timing jitter between the synchronized time-lens source and the mode-locked laser has to be minimized to extend the applications of this novel synchronized laser system to even shorter timescales below picoseconds

Summary

Introduction

Two-color synchronized ultrashort laser source is needed for a variety of physical, chemical and biomedical applications, such as pump-probe experiment[1] and nonlinear optical microscopy.[2,3] Tightly synchronized mode-locked laser[4] and synchronized pumped optical parametric oscillators[5] are commonly used for imaging purposes. If the relative timing jitter is comparable to the pulse width (i.e., on the order of picosecond), the imaging quality will su®er from dramatic deterioration.[4] Both intrinsic timing jitter of the modelocked laser[18] and the repetition rate drift of the mode-locked laser[19] have been theoretically identied as the origins of the relative timing jitter in the synchronized time-lens source. Based on the nature of this jitter source, wenally propose several strategies to reduce the relative timing jitter We expect that these results will provide guidelines for optimizing synchronization performance in experiments

Timing jitter induced by photodetection

Relative timing jitter introduced by photodetection

Strategies to suppress the relative timing jitter due to photodetection

Summary and Discussion