3D-visual laser-diode-based photoacoustic imaging.

We present a 3D-visual laser-diode-based photoacoustic imaging (LD-PAI) system with a pulsed semiconductor laser source, which has the properties of being inexpensive, portable, and durable. The laser source was operated at a wavelength of 905 nm with a repetition rate of 0.8 KHz. The energy density on the sample surface is about 2.35 mJ/cm(2) with a pulse energy as low as 5.6 μJ. By raster-scanning, preliminary 3D volumetric renderings of the knotted and helical blood vessel phantoms have been visualized integrally with an axial resolution of 1.1 mm and a lateral resolution of 0.5 mm, and typical 2D photoacoustic image slices with different thickness and orientation were produced with clarity for detailed comparison and analysis in 3D diagnostic visualization. In addition, the pulsed laser source was integrated with the optical lens group and the 3D adjustable rotational stage, with the result that the compact volume of the total radiation source is only 10 × 3 × 3 cm(3). Our goal is to significantly reduce the costs and sizes of the deep 3D-visual PAI system for future producibility.