Optical spectrometers enable contactless chemical analysis. However, decreasing both their size and cost appears to be a prerequisite to their widespread deployment. Chip-scale implementation of optical spectrometers still requires tackling two main challenges. First, operation over a broad spectral range extending to the infrared is required to enable covering the molecular absorption spectrum of a broad variety of materials. This is addressed in our work with an Micro-Electro Mechanical Systems (MEMS)-based Fourier transform infrared spectrometer with an embedded movable micro-mirror on a silicon chip. Second, fine spectral resolution Δλ is also required to facilitate screening over several chemicals. A fundamental limit states that Δλ is inversely proportional to the mirror motion range, which cannot exceed the chip size. To boost the spectral resolution beyond this limit, we propose the concept of parallel (or multi-core) FTIR, where multiple interferometers provide complementary optical paths using the same actuator and within the same chip. The concept scalability is validated with 4 interferometers, leading to approximately 3 times better spectral resolution. After the atmospheric contents of a greenhouse gas are monitored, the methane absorption bands are successfully measured and discriminated using the presented device.

光谱仪可实现非接触式化学分析。然而，减小它们的尺寸和成本似乎是它们广泛部署的先决条件。光谱仪的芯片级实现仍然需要解决两个主要挑战。首先，需要在扩展到红外的宽光谱范围内进行操作，以覆盖各种材料的分子吸收光谱。我们在使用基于微机电系统 (MEMS) 的傅立叶变换红外光谱仪的工作中解决了这个问题，该光谱仪在硅芯片上具有嵌入式可移动微镜。其次，还需要精细的光谱分辨率Δλ以促进对几种化学品的筛选。一个基本极限表明Δλ与镜面运动范围成反比，不能超过芯片尺寸。为了将光谱分辨率提高到超出此限制，我们提出了并行（或多核）FTIR 的概念，其中多个干涉仪使用相同的致动器并在相同的芯片内提供互补的光路。概念可扩展性通过 4 个干涉仪进行了验证，光谱分辨率提高了大约 3 倍。在监测温室气体的大气含量后，使用所提供的设备成功地测量和区分了甲烷吸收带。