Birefringence is one of key performance for optical functional crystals owing to their indispensable role in angle phase-matching or adjusting the polarization of light. In the past few decades, commercial birefringent crystals MgF₂, α-BaB₂O₄, CaCO₃, YVO₄, TiO₂, and LiNbO₃ with the moderate birefringence ranging from 0.01 to 0.2 have been widely used as polarization devices. Aimed at the demands in large birefringence or new applied spectral region, a series of crystals have appeared and possessed great potential as optical functional crystals with large birefringence. Herein, the authors review the developments of emergent candidates with the experimentally measured birefringence ≥ 0.1 in the field of optical materials. Recent efforts and active progress in exploring crystal with large birefringence according to different optical transmittance regions are discussed. The relationship between the crystal structures and birefringence was analyzed. It is hoped that this review will expound a clear perspective on structural chemistry of potential optical functional crystals with large birefringence and expedite the discovery of new birefringent crystals with expected properties to satisfy the urgent demands.

双折射是光学功能晶体的关键性能之一，因为它们在角度相位匹配或调节光的偏振中不可或缺。在过去的几十年里，商业双折射晶体MgF ₂、α -BaB ₂ O ₄、CaCO ₃、YVO ₄、TiO ₂和LiNbO ₃具有从 0.01 到 0.2 的中等双折射已被广泛用作偏振器件。针对大双折射或新应用光谱区的需求，出现了一系列晶体，具有作为大双折射光学功能晶体的巨大潜力。在此，作者回顾了光学材料领域实验测量的双折射≥ 0.1 的新兴候选者的发展。讨论了根据不同透光率区域探索大双折射晶体的最新努力和积极进展。分析了晶体结构与双折射之间的关系。