光学整流效应是产生宽带太赫兹波最有效的手段之一，基于光学整流效应产生太赫兹波的方法主要依靠抽运光与非线性晶体之间的相互作用。分别以5 mm的磷化镓（GaP）块状晶体和6 mm的GaP波导结构作为太赫兹波发射晶体，对具有相同功率的贝塞尔光束中心光斑和高斯光束的光学整流效率进行了对比研究。实验结果表明，在GaP块状晶体中，贝塞尔光束的光学整流效率是高斯光束的2.04倍；波导的特殊结构可以使抽运光和太赫兹波之间实现严格的相位匹配，贝塞尔光束的相对效率增加为3.46倍。两种抽运光产生的太赫兹波场均具有高斯分布特性，且贝塞尔光束产生的太赫兹波频谱具有明显的红移特征。贝塞尔光束能够提高光学整流效率，有助于实现高功率、紧凑型的太赫兹源，对推广太赫兹波的应用有显著意义。

Optical rectification (OR) is one of the most effective methods to generate broadband terahertz (THz) wave. The process of THz wave generation based on OR mainly depends on the interaction between the pump beam and the nonlinear crystal. The OR efficiencies in a 5 mm gallium phosphide (GaP) bulk crystal and a 6 mm GaP waveguide are compared between the central spot of a Bessel beam and a Gaussian beam with the same power. The experimental results show that the OR efficiency of the Bessel beam is 2.04 times larger than that of the Gaussian beam in the GaP bulk crystal, whereas the relative efficiency of the Bessel beam is increased to 3.46 times in the GaP waveguide due to perfect phase matching between the pump beam and the THz wave. The THz wave fields generated by both pumps have a Gaussian distribution, and the THz spectra generated by the Bessel beam have obvious red shifts. The fact that the Bessel beam could improve the OR efficiency will be helpful for achieving high-power and compact THz sources, which is valuable for various THz applications.