深圳大学学报理工版

太赫兹成像器件是太赫兹技术应用的关键之一.研制一种由分子束外延技术堆叠生长太赫兹量子阱探测器和近红外发光二极管制成的THz频率上转换成像器件,其45°入射角耦合器件峰值探测频率为5.2 THz,峰值响应率为0.22 A/W,噪声等效功率为5.2×1012 W/Hz0.5,可实现对太赫兹量子级联激光器光斑的清晰成像; 研制的金属光栅耦合器件可实现正入射成像,有效减小成像图形畸变,并且有利于制备大面积器件.阐述器件的工作原理、制备方法、基本性能和成像性能,并对器件电流-电压特性、成像质量、成像畸变原因等问题进行讨论.该器件利用无像素成像技术,无需低温读数电路,无需阵列倒装封装,为THz成像技术提供一种简便、高性能的途径.

Terahertz(THz)imaging device is one of the key technologies in THz technology applications. A THz frequency up-conversion imaging device made of THz quantum-well photodetectors and light-emitting diode(THz QWP-LEDs)is fabricated by stacking and growing THz QWPs and near-infrared LEDs with molecular beam epitaxy technology. The 45° facet coupler has a peak response of 0.22 A/W at the peak detection frequency of 5.2 THz and a noise equivalent power of 5.2×1012 W/Hz0.5. And the device also has the ability to image the spot of the terahertz quantum cascade laser(THz QCL)clearly. The developed metal grating coupler can achieve normal incidence imaging, effectively reduce the image distortion and is conducive to the preparation of large area devices. The working principle, fabrication method, basic performance and imaging performance of the devices are introduced in detail. The current-voltage characteristics, imaging quality and imaging distortion of the device are discussed. The devices have no need of cryogenic reading integrated circuits and flip-chip package based on pixel-free imaging technology. Therefore, the development of these devices can provide a simple way for high-performance THz imaging.

引言
1 器件工作原理
2 器件制备
3 器件性能表征
4 器件成像性能
5 结语

图1 THz QWP-LED器件能带图与工作原理<br/>Fig.1 Band-edge profiles and operation principle of THz QWP-LED

图1 THz QWP-LED器件能带图与工作原理
Fig.1 Band-edge profiles and operation principle of THz QWP-LED

图2 THz QWP-LED器件结构图<br/>Fig.2 The structure of the THz QWP-LEDs

图2 THz QWP-LED器件结构图
Fig.2 The structure of the THz QWP-LEDs

图3 45°入射耦合THz QWP-LED和相同量子阱结构的THz QWP,两种器件均在4.2 K工作温度时的V-I曲线及I-V曲线<br/>Fig.3 V-I curves and I-V curves of the 45°facet coupled THz QWP-LED. And a comparison THz QWP having the same multi-quantum well(MQW)parameters with the QWP part of the QWP-LED

图3 45°入射耦合THz QWP-LED和相同量子阱结构的THz QWP,两种器件均在4.2 K工作温度时的V-I曲线及I-V曲线
Fig.3 V-I curves and I-V curves of the 45°facet coupled THz QWP-LED. And a comparison THz QWP having the same multi-quantum well(MQW)parameters with the QWP part of the QWP-LED

图4 THz QWP-LED偏置电压1.7 V,工作温度5 K时的光谱与THz QCL工作温度10 K时的光谱<br/>Fig.4 Spectra of the THz QWP-LEDs biased at 1.7 V and 5 K and spectrum of THz QCL at 10 K in the imaging test

图4 THz QWP-LED偏置电压1.7 V,工作温度5 K时的光谱与THz QCL工作温度10 K时的光谱
Fig.4 Spectra of the THz QWP-LEDs biased at 1.7 V and 5 K and spectrum of THz QCL at 10 K in the imaging test

图5 45°入射耦合型THz QWP-LED峰值响应率及成像质量因子与器件工作电压的关系<br/>Fig.5 The peak response vs bias voltage and imaging quality factor vs bias voltage of the 45°facet coupled THz QWP-LED

图5 45°入射耦合型THz QWP-LED峰值响应率及成像质量因子与器件工作电压的关系
Fig.5 The peak response vs bias voltage and imaging quality factor vs bias voltage of the 45°facet coupled THz QWP-LED

图6 45°耦合型THz QWP-LED成像演示实验<br/>Fig.6 The imaging demonstration of 45° facet coupled THz QWP-LED

图6 45°耦合型THz QWP-LED成像演示实验
Fig.6 The imaging demonstration of 45° facet coupled THz QWP-LED

图7 金属光栅耦合型THz QWP-LED成像演示实验<br/>Fig.7 The imaging demonstration of metal grating coupled THz QWP-LED

图7 金属光栅耦合型THz QWP-LED成像演示实验
Fig.7 The imaging demonstration of metal grating coupled THz QWP-LED

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引言

1 器件工作原理

2 器件制备

3 器件性能表征

4 器件成像性能

5 结语

期刊信息

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