Professor Wang's research focuses on biomedical imaging. In particular, his lab has developed photoacoustic imaging that allows peering noninvasively into biological tissues. Compared to conventional optical microscopy, his techniques have increased the penetration by nearly two orders of magnitude, breaking through the optical diffusion limit. The Wang lab has invented or discovered functional photoacoustic tomography, 3D photoacoustic microscopy, optical-resolution photoacoustic microscopy, photoacoustic Doppler effect, photoacoustic reporter gene imaging, microwave-induced thermoacoustic tomography, universal photoacoustic reconstruction algorithm, time-reversed ultrasonically encoded optical focusing, and compressed ultrafast photography (world's fastest camera capable of 10 trillion frames per second). Combining rich optical contrast and scalable ultrasonic resolution, photoacoustic imaging is the only modality capable of providing multiscale high-resolution structural, functional, metabolic, and molecular imaging of organelles, cells, tissues, and organs as well as small-animal organisms in vivo. Broad applications include early-cancer detection, surgical guidance, and brain imaging. For example, it can help surgeons effectively remove breast cancer lumps, reducing the need for follow-up surgeries. Professor Wang's Monte Carlo model of photon transport in scattering media is used worldwide as a standard tool.