Image data acquired with fused multispectral information can be used for effective identification and navigation owing to additional information beyond human vision, including thermal distribution, night vision, and molecular composition. However, the construction of photodetectors with such capabilities is hindered by the structural complexity arising from the integration of multiple semiconductor junctions with distinct energy gaps and lattice constants. In this work, we develop a colloidal quantum-dot dual-mode detector capable of detecting, separating, and fusing photons from various wavelength ranges. Using three vertically stacked colloidal quantum-dot homojunctions with alternating polarity, single-band short-wave infrared imaging and fused-band imaging (short-wave and mid-wave infrared) can be achieved with the same detector by controlling bias polarity and magnitude. The dual-mode detectors show detectivity up to 8×1010 Jones at the fused-band mode and 3.1×1011 Jones at the single-band mode, respectively. Without image post-processing algorithms, the dual-mode detectors could provide both night vision and thermal information-enhanced night vision imaging capability. To the best of our knowledge, this is the first colloidal quantum-dot detector that can achieve such functionality. The operation mode can be changed at a high frequency up to 1.7 MHz, making it possible to achieve simultaneously dual-mode imaging and remote temperature sensing.

为了解决正一级频谱区域定位方法依赖先验模板或参考光波倾斜角的问题，提出一种利用频谱相位最大值自适应定位全息正一级频谱区域的方法。对预放大数字全息的频谱相位分布进行了理论分析，获知频谱相位的最大值处于正一级频谱的中心位置。利用频谱相位的最大值点与全息频谱振幅的三个区域（正一级、负一级和零级频谱区域）重心的最小距离，判定和定位全息正一级频谱区域。最后，以微孔阵列、相位台阶为样本进行了实验。实验结果与理论分析一致，该方法测量相位台阶的横向误差为3.7 μm，高度标准偏差为4.2%，能准确地定位正一级频谱的区域位置，而不依赖于先验模板或参考光波的倾斜角，为离轴全息频谱滤波提供了一种频谱区域自适应定位方法。