Signal Optimization for High-Resolution Imaging using Near-Field Optical Detection of Ultrasound

Simplified models for near-field optical probes are developed for the purpose of assessing their performance for detection of ultrasound. Based on either vertically-oriented or horizontal electric dipole radiators, these models show how the probe configuration can impact its performance. Typically used to gather signals with high spatial resolution, near-field probes have been shown to be useful for the study of ultrasound in nanometer-scale structures. The models developed in this work demonstrate the linearity of near-field signals for ultrasound detection and show that lateral spatial resolution can be degraded under conditions that maximize ultrasonic detection sensitivity.