A room‐temperature mid‐infrared (λ = 9 µm) heterodyne system based on high‐performance unipolar optoelectronic devices is presented. The local oscillator (LO) is a quantum cascade laser (QCL), while the receiver is an antenna coupled quantum well infrared photodetector optimized to operate in a microcavity configuration. Measurements of the saturation intensity show that these receivers have a linear response up to very high optical power, an essential feature for heterodyne detection. By providing an accurate passive stabilization of the LO, the heterodyne system reaches at room temperature the record value of noise equivalent power (NEP) of 30 pW at 9 µm and in the GHz frequency range. Finally, it is demonstrated that the injection of microwave signal into the receivers shifts the heterodyne beating over the large bandwidth of the devices. This mixing property is a unique valuable function of these devices for signal treatment in compact QCL‐based systems.

中文翻译：

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室温贴片天线接收器在中红外（λ≈9 µm）外差系统中的混合特性

提出了一种基于高性能单极光电器件的室温中红外（λ= 9 µm）外差系统。本地振荡器（LO）是量子级联激光器（QCL），而接收器是天线耦合的量子阱红外光电探测器，经过优化可在微腔配置中运行。饱和强度的测量结果表明，这些接收器在非常高的光功率下具有线性响应，这是外差检测的基本功能。通过提供本振的准确无源稳定，外差系统在室温下达到了9 µm且在GHz频率范围内30 pW的噪声等效功率（NEP）的记录值。最后，证明了将微波信号注入接收器可在设备的大带宽范围内移动外差拍打。