摘要:
由材料參數(shù)測試和器件響應(yīng)率測試證實,LiNbO3晶體的熱釋電響應(yīng)率優(yōu)值Mv為一般公認值的二倍。而且當(dāng)溫度升高時,Mv緩慢降低,并不出現(xiàn)某些文獻所預(yù)示的明顯增加。著重研究了LiNbO3探測器在高功率密度連續(xù)激光輻照下的輸出特性。研究結(jié)果表明,在相同條件下,LiNbO3探測器的輸出開始偏離線性所對應(yīng)的最大功率密度遠高于LiTaO3。仔細測定了LiNbO3晶體的固有介質(zhì)損耗,并據(jù)此估計LiNbO3器件探測率的極限值。分析表明,就制備背景限探測率的器件的潛力而言,LiNbO3不低于TGS。
Abstract:
Based on the experimental results obtained from both the measurement of material parameters and device responsivity, it is verified that the pyroeleetric responsivity figure of merit of LiNbO3 crystal, Mv is twice as high as that generaly acknowledged value. Furthermore, when the temperature rises, Mv slowly decreases rather than in-creases evidently with temperature as reported in certain literatures. In this paper, the output characteritics of LiNbO3 pyroeleetric detector which is irradiated by the high-power CW CO2 laser has been investigated. The results show that the maximum power density at which the output characteristics of LiNbO3 detector begin to deviate from linear range far exceeds that of LiTaO3 detector under the same conditions. We have carefully measured the intrinsic dielectric loss tgd of LiNbO3 crystal. The value obtained can be used to estimate the detectivity limit of LiNbO3 pyroelectric detector. Detailed analysis proves that, for producing the pyroelectric detector with background limited performance, its figure of merit of LiNbO3 crystal is favorable, and no loss than those of most commonly used materials, such as TGS.
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