Focused polarization hologram with arbitrary polarization to a specified polarization conversion.

Polarization devices play a key role in many optical technologies and applications. However, traditional polarization devices are often large and lack integration, and achieving polarization conversion typically requires combining multiple devices, which makes it challenging to realize integrated optical systems. Following the current trend of optical devices, we propose a method using polarization holographic exposure to prepare polarization conversion devices. This approach allows for the fabrication of devices that can convert arbitrary polarization states into specified polarization states while also incorporating a focusing function. Specifically, two types of polarization conversion holograms are fabricated. One is a linear polarizer with a focusing function, and the other is a circular polarizer with a focusing function. Their polarization extinction ratio is around 35 dB, which has a certain competitiveness in similar devices. This method simplifies the preparation process of multifunctional polarizing devices while ensuring their performance. Our work has potential applications in the fields such as polarization emission, imaging, and sensing. Additionally, this approach broadens the design concept of polarization conversion devices, which may promote the development of optical devices with lower cost and higher integration.