There are straightforward motivations for miniaturizing an optical spectrometer. If an instrument can be made smaller, it often will also consume less power, enabling it to be portable and eventually handheld. This allows the spectrometer to be taken to the sample, as opposed to the sample to the spectrometer, and this typically leads to increased productivity in traditional applications. Small size also often implies lower cost, and this opens up nontraditional applications. In recent years, improvements in optics, electronics, and detectors have enabled the design and manufacture of many small optical spectrometers (1-4), and some specific instruments have been described in articles in Spectroscopy by John Coates (5-9). The purpose of this article is not to describe these miniature spectrometers and their applications in detail, but to outline the design principles and approaches to these instruments - what underlies the choices the developers have made, and what those imply for performance. This article describes various miniaturization techniques and focuses on the mid-infrared; subsequent articles will examine near-infrared, UV-vis, and Raman spectrometers. Miniature spectrometers can be regarded as a "disruptive technology" as described by Christenson (10). He gives several examples of products based upon innovative technologies whose initial performance was significantly less than that of mature and established products. He also notes that the performance of mature products could overshoot the market and give customers more performance than they really require. Innovative products found niches at the low-price end of the market, in new applications, where their performance was "good enough." But because the performance of these newer products progressed faster than their mature counterparts, they rapidly became competitive with these mature products and eventually met the performance requirements of the majority of the market. This scenario can lead to the demise of the previously dominant products and technologies.
展开▼
