VCSEL pulse length optimization for clinical photoacoustic imaging

VCSEL-based illumination offers great potential for clinical photoacoustic imaging. One major advantage of VCSEL-based light sources is the tunable pulse length, which enables to maximize the recorded energy by matching both the size of the target object and the bandwidth of the ultrasound transducer. Theoretical and practical understanding of pulse length tuning is critical for optimal utilization of VCSELs in clinical photoacoustic scanners. In this study, we demonstrate, using in silico simulations and phantom measurements, that for a target absorber of a given size, maximal sensitivity is reached for a specific pulse length. We also validate using in vivo data that VCSEL illumination—when using an optimal pulse length—offers a high image quality suitable for clinical applications. This proof of concept study paves the way for optimizing the design of next-generation VCSEL modules for photoacoustic imaging.