Study of high repetition rate noncontact photoacoustic image using pulse laser diode

Abstract

The disadvantage of conventional noncontact photoacoustic imaging is that there is a change in the interference signal according to the initial phase. To overcome this problem, the quadrature signal is calculated using the characteristics of 3x3 coupler, and the interference signal is reconstruction so that there is almost no signal change. Nd: YAG, which is mainly used as an excitation laser when constructing a photoacoustic imaging system, is expensive to purchase when the system is first manufactured. In order to solve this problem, a photoacoustic system was constructed using a 905nm pulsed laser diode. The resolution of the constructed system was proved to be 370μm using the knife-edge test method.