MINIATURIZED IMAGING SPECTROMETERS: Prism-based spectrometers tackle today's miniaturization requirements

摘要

Because a prism transmits 90percent of light over an extended wavelength range, matching it to a CCD detector with close to 90percent quantum efficiency creates a nearly ideal system that, with some tradeoffs, can be miniaturized to meet portable spectroscopy application needs. It is truly said that form follows function; however, increased miniaturization inevitably collides with practical realities. Surprisingly, however, technologies over 300 years old are finally experiencing a rebirth in cutting-edge applications. Sir Isaac Newton first described the use of a prism to display the colors present in the sun's light in 1666. This promising beginning was soon usurped by the diffraction grating and by the late 1800s grating-based spectrometers became the de facto standard. But by the year 2000, grating-spectrometer development had more or less hit a plateau, failing to satisfy some of the more demanding and emerging applications that often require miniature spectrometers or microspectrometers in a handheld or portable format.