In recent years, optical crystals for 1.3 μm all-solid-state passively Q-switched lasers have been widely studied due to their eye-safe band, atmospheric transmission characteristics, compactness, and low cost. They are used in the fields of high-precision laser radar, biomedical applications, fine processing. this review, we focus on three types as gain media: neodymium-doped vanadate (Nd:YVO4...