Polarization control of dual-wavelength high peak power Raman lasers based on passively Q-switched technology and yttrium vanadate (YVO₄) crystal are widely used for generating novel laser sources, terahertz wave, material processing, and manipulating microparticles. However, the Raman lasers are usually linear polarization. Here, elliptical polarizations with controllable ellipticity and azimuthal angle are manipulated by adjusting the crystalline orientation of a-cut YVO₄ crystal in a passively Q-switched Raman laser constructed with a Cr⁴⁺,Nd³⁺:Y₃Al₅O₁₂ (Cr,Nd:YAG) crystal and a a-cut YVO₄ crystal. The ellipticity of the elliptically polarized dual-wavelength Raman laser varies in a sinusoid modulation as a-cut YVO₄ crystal rotates with respect to the major axis of the intracavity fundamental laser and increases with applied pump power. The azimuthal angle varies in the same speed as a-cut YVO₄ crystal rotates. Anisotropic behavior of sinusoidal modulation of output power, pulse energy, and peak power is observed as a-cut YVO₄ crystal rotates. There are four peaks and four troughs for ellipticity, output power, pulse energy, and peak power within a 360° rotation of a-cut YVO₄ crystal. This work provides a solid and simple method for developing elliptical polarization controllable dual-wavelength passively Q-switched Raman laser with high peak power for various potential applications.

中文翻译：

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椭圆偏振被动调Q拉曼激光器晶体取向的偏振控制

基于被动调Q技术和钒酸钇（YVO ₄）晶体的双波长高峰值功率拉曼激光器的偏振控制被广泛用于产生新型激光源、太赫兹波、材料加工和操纵微粒。然而，拉曼激光器通常是线偏振的。在此，具有可控椭圆率和方位角椭圆极化由调整的结晶取向操纵一个-cut YVO ₄晶体的被动Q开关激光的拉曼带的Cr构成⁴⁺，钕³⁺：Y ₃的Al ₅ Ô ₁₂（ Cr,Nd:YAG) 晶体和 a-cut YVO ₄水晶。椭圆偏振双波长拉曼激光器的椭圆率在正弦调制作为变化一个-cut YVO ₄相对于所述内腔基本激光和随外加泵功率增加的长轴晶体旋转。方位角在相同的速度而变化一个-cut YVO ₄晶体旋转。被观察为输出功率，脉冲能量，和峰值功率的正弦调制的各向异性行为一个-cut YVO ₄晶体旋转。有一个360°的旋转范围内的四个峰和四个波谷为椭圆，输出功率，脉冲能量，峰值功率一个-cut YVO ₄水晶。这项工作为开发具有高峰值功率的椭圆偏振可控双波长被动调Q拉曼激光器提供了一种可靠而简单的方法，可用于各种潜在应用。