Capturing the distinctive spectral fingerprints of molecules in the infrared (IR) region is of vital importance in gas detection. However, it is still limited by the resolution, sensitivity and signal to noise ratio of IR detectors. Here, a broadband frequency conversion scheme from the middle IR band (MIR) to the telecom band based on four-wave mixing process is proposed and theoretically investigated, combining the advantages of well-established detectors in the telecom band and unique molecular vibrations in the MIR band. A flat and low dispersion profile is generated in an asymmetric Ge-As-Se/SiO ₂ hybrid waveguide, which exhibits four zero-dispersion wavelengths and a dispersion variation of sub-20 ps/nm/km. Furthermore, taking advantage of the high order phase-matching, an ultra-broad 3-dB continuous wavelength conversion bandwidth covering 1454–4521 nm is achieved, which to the best of our knowledge is the widest frequency conversion bandwidth in the chip-scale devices. In addition, a fabrication scheme is proposed for the precise manipulation of dispersion. It holds great potential for practical applications in photonic integrated gas sensing, biomedical diagnostics.

中文翻译：

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通过硫族化物/ Sio ₂混合波导桥接中红外和电信频段的宽带频率转换的理论研究

在气体检测中，捕获红外（IR）区域中分子的独特光谱指纹至关重要。但是，它仍然受到红外探测器的分辨率，灵敏度和信噪比的限制。在此，结合传统的检测器在电信频段的优势和在电信频段中独特的分子振动的优点，提出并从理论上研究了基于四波混频过程的从中红外频段（MIR）到电信频段的宽带频率转换方案。中红外波段。在不对称的Ge-As-Se / SiO _2中产生平坦且低色散的轮廓 混合波导，具有四个零色散波长和小于20 ps / nm / km的色散变化。此外，利用高阶相位匹配的优势，获得了覆盖1454–4521 nm的超宽3dB连续波长转换带宽，据我们所知，这是芯片级器件中最宽的频率转换带宽。另外，提出了一种用于精确控制分散的制造方案。它在光子集成气体传感，生物医学诊断中的实际应用具有巨大潜力。