Development of a Miniature Static Imaging Fourier Transform Spectrometer (SIFTS)

微型静态成像傅里叶变换光谱仪 (SIFTS) 的开发

• 批准号: NE/I00114X/1
• 负责人: Timothy Nightingale
• 金额: $ 10.35万
• 依托单位: Science and Technology Facilities Council
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI00114X%2F1
• 关键词: Development; Miniature; Static; Imaging; Fourier

This aim of this project is to develop a miniaturised Fourier transform spectrometer, known as a Static Imaging Fourier Transform Spectrometer (SIFTS). This instrument utilises a simple optical arrangement to split and then recombine light to form a complex modulated interference pattern (known as an interferogram). The frequency spectrum of the source radiation is obtained by applying a Fourier transform to the recorded interferogram. The static optical configuration is arranged such that the interferogram is dispersed spatially along a focal plane, where a detector can be positioned. In this configuration the interferogram is at discrete locations determined by the architecture of the pixel elements within the detector array. Unlike conventional Michelson FTIR spectrometers, the SIFTS design is compact (50 mm by 50 mm by 30 mm) and lightweight (~0.4 kg). As the optical configuration is static and there is no need to use a scanning mirror to obtain an interferogram, the acquisition time is limited only by the frame rate of the detector array (~1 x 10-4 s-1), which gives the SIFTS a significant temporal sampling advantage over traditional FTIR spectrometers. A breadboard version of the SIFTS has been built at RAL, which has successfully demonstrated the principles behind the technology. The breadboard instrument operates in the ultra-violet and visible spectral region, using a commercially available charged coupled device (CCD) detector array. By coupling a tungsten halogen light source to the input of the SIFTS instrument via fibre optics, it has been possible to record transmission and reflectance spectra from various targets in the spectral region 400 to 1100 nm. The fundamental rotation-vibration absorption bands associated with gas molecules are, however, located in the near and mid infrared part of the spectrum. Therefore it is intended to develop an infrared version of the SIFTS instrument to maximise the sensitivity of trace gas measurements. This project will adapt this proven technique for use in the near infrared, so that the instrument is spectrally sensitive in the region where key gases are active. This will involve optimising the existing design for use in the infrared, by incorporating optical elements and a detector array that are sensitive at longer wavelengths.

该项目的目的是开发一种小型化的傅立叶变换光谱仪，即静态成像傅立叶变换光谱仪（SIFTS）。这种仪器利用一种简单的光学装置来分裂光，然后重新组合光，形成一个复杂的调制干涉图样（称为干涉图）。源辐射的频谱是通过对记录的干涉图进行傅里叶变换得到的。静态光学结构的布置使得干涉图沿可放置探测器的焦平面在空间上分散。在这种配置中，干涉图位于由探测器阵列内像素元素的结构决定的离散位置。与传统的迈克尔逊FTIR光谱仪不同，SIFTS设计紧凑（50mm × 50mm × 30mm），重量轻（~0.4 kg）。由于光学结构是静态的，不需要使用扫描镜来获取干涉图，因此采集时间仅受探测器阵列的帧速率（~1 x 10-4 s-1）的限制，这使得SIFTS比传统的FTIR光谱仪具有显着的时间采样优势。在RAL已经建立了SIFTS的面包板版本，它已经成功地演示了该技术背后的原理。面包板仪器在紫外和可见光谱区域工作，使用市售的电荷耦合器件（CCD）探测器阵列。通过光纤将卤钨光源耦合到SIFTS仪器的输入端，可以记录400 ~ 1100nm光谱区域内不同目标的透射光谱和反射光谱。然而，与气体分子相关的基本旋转振动吸收带位于光谱的近红外和中红外部分。因此，打算开发一种红外版的SIFTS仪器，以最大限度地提高痕量气体测量的灵敏度。该项目将采用这种经过验证的技术用于近红外，以便该仪器在关键气体活跃的区域具有光谱敏感性。这将包括优化现有的红外设计，通过结合光学元件和在更长的波长敏感的探测器阵列。