Focus Sharpens on Miniature Optical Spectrometers at Pittcon

American Laboratory
May 06, 2014
By Matt Wilkinson

Optical spectroscopy often seems to be somewhat overlooked at Pittcon®, with much of the attention focusing on hyphenated technologies such as GC/MS or ultrahigh-performance liquid chromatography (UHPLC)-MS/MS. Over recent years, renewed interest in the area has been largely led by those products that could either reduce sample volumes or take the analyzer to the sample. This year, there was also activity in combined imaging and spectroscopy instruments, many of which were covered in Barbara Foster’s review: Integrating-Microscopy-Into-the-Analytical-Scheme-A-Pittcon-2014- Microscopy-Review/.

Miniaturizing the future of spectrometer design

There were several innovations on display that promise to further miniaturize and reduce the cost of future optical spectrometers.

This year’s winner of the Pittcon Editors’ Gold Award was the DLP® NIRscan™ evaluation module from semiconductor expert Texas Instruments (Dallas, TX;, which is a complete optical unit that contains no mechanical parts. The DLP NIRscan is based upon the company’s DLP4500NIR microelectromechanical system (MEMS) device, which is optimized for use with near-infrared (NIR) light in the 700- to 2500-nm range. The MEMS device contains more than 1 million digitally programmable micromirrors that can be easily controlled to employ adaptive scanning techniques to optimize material analysis.

Around the micromirrors, the company has assembled optical slits, diffraction gratings, detectors, and embedded processors to provide an integrated optical unit without mechanical parts to give spectrometer developers a working central unit, around which they can build their specific NIR spectroscopy instrument.

When paired with a single element detector, the DLP4500NIR can replace expensive linear array detectors to create high-performance yet affordable spectrometer designs. The micromirrors enable spectral resolution and wavelength range refinement, adjustment of integration time, and equalize light throughput such that signal-to-noise ratios greater that 30,000:1 can be achieved.