Research on the influence of ring hole array metamaterial on the performance of pyroelectric terahertz detectors

In order to improve the detection performance of 0.1-1THz terahertz wave, a new lithium tantalate pyroelectric terahertz detector based on ring hole array metamaterial is proposed. The quantitative influence of the characteristic parameters such as inner diameter, outer diameter, period and thickness on the transmission bandwidth and transmittance of ring hole array metamaterials was analyzed by simulation. The mechanism of the different combinations of ring hole array metamaterials and pyroelectric detectors on the detection bandwidth and detection rate of terahertz waves was clarified. The lithium tantalate pyroelectric terahertz detectors of the ring hole array metamaterial ware fabricated by the MEMS technology. The transmission of the ring hole array metamaterial and the noise equivalent power of the metamaterial detector at different frequencies were tested. The results show that the transmittance of the fabricated ring hole array metamaterial is greater than 40% at 0.25-0.65THz, and bandpass filtering is realized. When the ring hole array metamaterial and the pyroelectric detector maintain a sufficient distance, the noise equivalent power of the detector at 0.315THz is 11.29μW/Hz0.5, which is 6.3% of the 0.1THz noise equivalent power (outside the bandpass band), so the bandpass detection is achieved. When the ring hole array metamaterial is attached to the detector, the noise equivalent power of the metamaterial detector at 0.315THz is 4.64μW/Hz0.5, which is 29.4% of the detector without the ring hole array metamaterial, so the narrowband detection is achieved. The above conclusions show that the pyroelectric terahertz detector based on the ring hole array metamaterial can realize the bandpass and narrowband detection of specific frequency band in applications such as biological imaging and macromolecular detection.