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.