采用高温固相法合成了一种新型的Yb³⁺和Ho³⁺共掺杂的Ba₃In（PO₄）₃上转换荧光粉，并研究了其晶体结构、上转换发光及能量传递机制。在980 nm激光激发下，Yb³⁺吸收能量并传递至Ho³⁺；此外，激光功率对于荧光粉发光颜色无明显影响，发光颜色主要集中在橙黄色区域（0.543，0.452）。测得0.05Yb³⁺和0.032Ho³⁺掺杂的荧光粉的荧光寿命约为467.61 μs。还测量了该荧光粉温度依赖的发光光谱，并计算了其用作光学温度计的绝对灵敏度（S_a）和相对灵敏度（S_r）。结果表明，该荧光粉具有良好的热稳定性，423 K时的发射强度仍保持在室温的81.68%，⁵S₂，⁵F₄→⁵I₈、⁵F₅→⁵I₈跃迁的ΔE分别约为0.19 eV和0.27 eV。此外，其S_a和S_r最大值分别为0.31%·K^-1和0.09%·K^-1（573 K）。

Photoacoustic microscopy (PAM) has quickly developed into a noninvasive biomedical imaging technique to achieve detection, diagnosis, and monitoring. Compared with Q-switched neodymium-doped yttrium aluminum garnet or optical parametric oscillator lasers, a low-cost and small-size laser diode (LD) used as an alternative light source is conducive to achieving the miniaturization and integration for preclinical transformation. However, the LD’s low peak output power needs the high numerical aperture objective to attain tight focus, which limits the working distance (WD) of the system in only 2–3 mm, resulting in not achieving the backward coaxial confocal mode. Here, we present a compact visible LD-based PAM system with a reflective objective to achieve a 22 mm long WD and a 10 µm lateral resolution. Different depth subcutaneous microvascular networks in label-free mouse ears have successfully reappeared in vivo with a signal-to-noise ratio up to 14 dB by a confocal alignment. It will be a promising tool to develop into a handy tool for subcutaneous blood vessel imaging.