Light Sci. Appl. 6, e17103 (2017)

Heart surgery and other complex operations could be made easier thanks to the use of optically generated ultrasound imaging that can be performed at the end of a needle. A team of scientists from University College London and Queen Mary University of London in the UK have developed an imaging system whereby two optical fibres are placed inside a hollow needle to locally generate and detect ultrasound. The generation fibre is equipped with a special absorbing coating at the end that on exposure to laser light generates ultrasound due to the photoacoustic effect. Ultrasound reflections from the surrounding tissue are detected using light in the receiving fibre, which is passed into a Fabry–Perot cavity. The approach has been demonstrated with cardiac surgery performed on a pig.