电光调制在被动综合孔径成像探测中的应用

介绍了一种新型被动综合孔径成像探测方法:视场辐射信号被接收和放大后,通过电光幅度调制将其幅度和相位信息加载到光波上,经光纤传输在末端形成阵列,通过光学系统直接成像,将视场实时恢复出来.该方法可实现工作在微波、毫米波和太赫兹波段的高分辨力实时成像探测的目的.深入分析了电光调制器在综合孔径成像探测中的应用,建立电光调制模型,讨论了在小信号调制下的电光幅度调制近似理论.通过数值计算与仿真分析,得到综合孔径成像探测中电光调制器的调制信号强度限制的有关结论.结果表明,利用上变频电光调制技术和光信息处理,所得到的成像仿真图的半峰全宽和信噪比性能都优于传统的基于下变频技术的成像仿真结果.

Application of Electro-Optic Modulation in Passive Synthetic Aperture Imaging Detection

A new passive synthetic aperture imaging detection method is presented. The radiation signal of field of view is received and amplified, and then the amplitude and phase information of the amplified signal is modulated to an optical carrier by electro-optic modulator. The optical signal is transmitted by fibers and a fiber array is shaped by the end of the fibers .The image is formed synchronously and directly by an optical system using the fiber array. The imaging approach can be used in extremely high resolution detection at microwave, millimeter wave, and terahertz frequencies. The application of the electro-optic modulation technique in passived synthetic aperture imaging is analyzed deeply and the model of electro-optic modulation is established. And the approximation of small signal modulation in the electro-optic modulation is discussed. By simulating computation and analysis, the intensity constraint of the modulated signal in an electro-optic modulator is gained. Result shows that the full-width at half maximum (FWHM) and signal-to-noise ratio (SNR) with upconversion electro-optic modulation and optical information processing are both better than those with traditional downconversion imaging technique.