A new technology that includes a flexible holographic recording system using photo-thermo-refractive (PTR) glass is demonstrated for creating so-called ‘holographic phase masks’ or HPMs. These diffractive optical elements are permanently recorded in the PTR glass, can be multiplexed as with normal holograms, do not require electric power to operate, and can perform near arbitrary beam phase transformations. The holographic setup includes a spatial light modulator that enables recording transmitting volume Bragg gratings (VBGs) with arbitrary phase patterns encoded into them. As a result, the desirable phase pattern is introduced in a beam that is diffracted by the VBG. These HPMs are tunable within the visible and near IR spectral regions and can be made achromatic, with spectral widths of up to 50 nm. Furthermore, they tolerate laser power densities on the order of several kW cm⁻². Applications of HPMs include high-power, broadband laser beam shaping and modal analysis of complex beams profiles, both of which are demonstrated here.

展示了一种新技术，其中包括使用光热折射 (PTR) 玻璃的灵活全息记录系统，用于创建所谓的“全息相位掩模”或 HPM。这些衍射光学元件永久记录在 PTR 玻璃中，可以像普通全息图一样多路复用，不需要电力来操作，并且可以执行近乎任意的光束相变。全息设置包括一个空间光调制器，可以记录具有任意相位模式的传输体布拉格光栅 (VBG)。结果，理想的相位图案被引入到被 VBG 衍射的光束中。这些 HPM 在可见光和近红外光谱区域内可调，并且可以制成消色差，光谱宽度高达 50 nm。此外，^－2．HPM 的应用包括高功率、宽带激光束成形和复杂光束轮廓的模态分析，这两者都在此处进行了演示。