Photoacoustic imaging (PAI), an emerging imaging technique, exploits the merits of both optical and ultrasound imaging, equipped with optical contrast and deep penetration. Typical linear PAI relies on a nanosecond laser pulse to induce photoacoustic signals. To construct a multi-wavelength PAI system, a multi-wavelength nano-second laser source is required, which greatly increases the cost of the PAI system. However, according to the nonlinear photoacoustic effect, the amplitude of the photoacoustic signals will vary with different base temperatures of the tissue. Therefore, using continuous-wave lasers with different wavelengths to induce different temperature variations at the same point of the tissue, and then using a single-wavelength pulsed laser to induce photoacoustic signals has been an alternative method to achieve multi-wavelength PAI. In this paper, based on the nonlinear photoacoustic effect, we developed a continuous-wave multi-wavelength laser source to cut down the cost of the conventional multi-wavelength PAI system. The principle will be introduced firstly, followed by qualitative and quantitative experiments.

中文翻译：

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基于便携式连续波激光二极管模块的低成本多波长光声成像。

光声成像（PAI）是一种新兴的成像技术，它利用了光学和超声成像的优点，并具有光学对比度和深度穿透能力。典型的线性PAI依赖于纳秒级的激光脉冲来诱导光声信号。为了构建多波长PAI系统，需要多波长纳秒激光源，这大大增加了PAI系统的成本。然而，根据非线性光声效应，光声信号的幅度将随着组织的不同基础温度而变化。因此，使用具有不同波长的连续波激光器在组织的同一点处诱导不同的温度变化，然后使用单波长脉冲激光器来诱导光声信号已经成为实现多波长PAI的替代方法。本文基于非线性光声效应，开发了一种连续波多波长激光源，以降低传统的多波长PAI系统的成本。首先介绍该原理，然后进行定性和定量实验。