We present a theoretical analysis of power redistribution among field components when a linearly polarized ordinary Gaussian beam propagates at an arbitrary angle $\theta$ relative to the optical axis of a uniaxial crystal. Closed-form expressions for the fractional power of each Cartesian component are derived as functions of both $\theta$ and the normalized crystal thickness $y_r$. Each power function separates into a thickness-independent asymptotic term and an oscillatory term driven by ordinary-extraordinary eigenmode interference. In the thick-crystal limit, the known on-axis result is recovered $(P_z=25\% \text{at} \theta =0^{\circ })$, but finite-thickness oblique propagation substantially exceeds this ceiling: at $\theta \approx 0.8^{\circ }$ and $y_r\approx 30$, the $z$ component reaches $P_z\approx 36.2\%$ of the total input power, a $45\%$ relative enhancement achievable at a physical crystal length of only $\approx 3.7\mathrm{mm}$. In the small-angle regime $(\theta \lesssim 2.5^{\circ })$, the power distribution is highly sensitive to the propagation angle, with a change of $\approx 1^{\circ }\text{–}{2}^{\circ }$ shifting $P_x$ by up to 0.34. This sensitivity originates from the quadratic dependence of the ordinary-extraordinary phase mismatch on $\theta$ near parallel propagation and grows linearly with crystal thickness. A closed-form characteristic sensitivity angle is derived, providing explicit design rules for engineering the sensitivity window. Three distinct operational regimes are identified, offering quantitative guidelines for optimizing power conversion and polarization control in uniaxial-crystal-based optical systems.

Close

PrevNext

View figure in article

• Optics & lasers
• Structured light
• Optical materials & elements