Integration and Characterization of LiTaO₃ Single Crystal Film Pyroelectric Sensor Using Mid-Infrared Metamaterial Perfect Absorber

An infrared sensor with Au/SiO ₂ /Au metamaterial perfect absorber (MPA) structure and Crystal ion slicing (CIS) fabricated LiTaO ₃ single crystal film to realize wavelength-selective function was proposed and fabricated in this paper. The Au/SiO ₂ /Au multilayer MPA exhibited outstanding wavelength selectivity at $4.04\mu \text{m}$ with a maximum absorbance of 98% and the spectral voltage response of sensor highly agreed with it. Meanwhile, the sensor performed stable angle independency with radiation incident angle from 0° to 50°. After integration, this sensor showed maximum voltage responsivity of ${1.7} \times {10}^{{4}}\text{V}$ /W, maximum detectivity of ${1.7} \times {10}^{{8}}$ cmHz ^1/2 /W, and 5.8ms response time. These results demonstrate the promising application prospect of high specific and fast response pyroelectric infrared sensor achieved by integrating MPA with LiTaO ₃ thin film.