In this study, the main focus is laid on the design of an optoelectronic converter as a part of the quantum radar to enhance the entanglement between retained and returned modes at high temperatures. The electro-opto-mechanical converter has been widely studied, and the results showed that the operation at high temperature is so crucial to generate and preserve the entanglement between modes. The main problem arises because the mechanical part operating at a low frequency leads to a large number of thermally excited photons, and eventually, the entanglement between modes becomes lost. To solve the problem, we replace the mechanical part with the optoelectronic components. The optical cavity is coupled to the microwave cavity in the newly designed system through a Varactor diode excited by a photodetector. As the main goal, to improve the entanglement sustainability, the effect of the coupling factor of the microwave cavity to photodetector is investigated. The results show that the mentioned factor creates some degrees of freedom to enhance the entanglement at high temperatures compared to the electro-opto-mechanical converter. At some specific values of the coupling factor, the retained and returned fields remained completely entangled up to 5.5 K and partially entangled around 50 K.

中文翻译：

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在量子雷达中使用光电转换器改善纠缠可持续性（干涉式物体感测）

在这项研究中，主要重点放在作为量子雷达一部分的光电转换器的设计上，以增强高温下保留模和返回模之间的纠缠。对电光-机械转换器进行了广泛的研究，结果表明，在高温下运行对于产生和保持模式之间的纠缠至关重要。出现主要问题的原因是，在低频下工作的机械部件会导致大量的热激发光子，并最终导致模之间的纠缠丢失。为了解决该问题，我们将机械零件替换为光电组件。光学腔通过由光电探测器激发的变容二极管耦合到新设计的系统中的微波腔。作为主要目标，为了提高纠缠的可持续性，研究了微波腔与光电探测器耦合系数的影响。结果表明，与电光-机械转换器相比，上述因素在高温下产生一定程度的自由度，以增强纠缠度。在某些特定的耦合因子值下，保留场和返回场保持完全纠缠直至5.5 K，部分纠缠在50 K附近。