摘要
Photoacoustic(PA)imaging is a promising non-invasive and non-ionizing biomedical imaging modality that emerged in recent years.The articles presented in this special issue describe some of newest progress in this field.We are extremely grateful to all contributing authors.The first part of the issue covers new laser source devel-opment,including fiber lasers and laser diodes.The sec-ond part is dedicated to improving the image resolution through chronic cranial window techniques,virtual-point concept,fast polygon scanning,and Fabry Perot sensing.The third part shows the basic principles of photoacous-tic/ultrasound imaging and its applications.