Laser scanning laser diode photoacoustic microscopy system

Abstract

The development of low-cost and fast photoacoustic microscopy systems enhances the clinical applicability of photoacoustic imaging systems. To this end, we present a laser scanning laser diode-based photoacoustic microscopy system. In this system, a 905 nm, 325 W maximum output peak power pulsed laser diode with 50 ns pulsewidth is utilized as the light source. A combination of aspheric and cylindrical lenses is used for collimation of the laser diode beam. Two galvanometer scanning mirrors steer the beam across a focusing aspheric lens. The lateral resolution of the system was measured to be ∼21 μm using edge spread function estimation. No averaging was performed during data acquisition. The imaging speed is ∼370 A-lines per second. Photoacoustic microscopy images of human hairs, ex vivo mouse ear, and ex vivo porcine ovary are presented to demonstrate the feasibility and potentials of the proposed system.

Review of Low-Cost Photoacoustic Sensing and Imaging Based on Laser Diode and Light-Emitting Diode

“…To solve this challenge, firstly, the most direct method is to improve the output power of these semiconductor diodes to enhance the SNR. To the best of our best knowledge, the maximum output peak power of 325 W 905 nm laser diode with 50 ns pulsed duration was demonstrated to excite the PA signals with sufficient SNR (18 dB for imaging porcine ovary ex vivo) and no averaging was required [ 34 ]. Secondly, the most commanding and simple method to increase SNR is to average hundreds of PA signals at the same irradiation point, which will limit the imaging or detection speed.…”

“…Thus, improving the energy is of paramount importance. The proposed PAM system reported in Reference [ 34 ] utilizes the laser source that can output 325 W peak power pulse within 50 ns. It is not necessary for averaging during data acquisition in this system.…”

Design of photoacoustic microscope system based on labVIEW platform

“…In this paper, a "virtual instrument" (VI) is used to design a small-scale high-resolution photoacoustic microscopy imaging system. The excitation source uses laser diodes with small size, low price and high repetition rate [15][16][17][18]. It was initially applied to the imaging of subcutaneous vascular imaging in mouse ears.…”

Photoacoustic Signal Enhancement: Towards Utilization of Low Energy Laser Diodes in Real-Time Photoacoustic Imaging

“…Low-energy pulse laser diodes (LE-PLD) are used as a light source in cost-effective PA imaging systems [ 14 , 15 , 16 ]. The PA signals generated by LE-PLD usually have a very low signal-to-noise ratio (SNR) and the quality of reconstructed images is not satisfactory [ 17 ].…”