This project is focussed on developing an optical imaging technology called photoacoustic imaging. Photoacoustic imaging is able to distinguish healthy tissue from cancerous tissue during breast surgery and could one day eliminate the need for repeat surgeries. The technology uses a pulsed laser to selectively build up pressure in some tissues and microphones to listen for sound as the pressure dissipates. After reconstruction, the sound recordings are converted back into a pressure map representative of the tissues. The project funds will support two PhD students. The first student will study a hand-held photoacoustic probe that surgeons can one day use to image tissue during surgery. The second student will study a new type of sound recorder that could revolutionize how photoacoustic images are captured. Advancements made by both students could one day make photoacoustic imaging a routine method to screen for cancer and aide its removal during surgery.