Spectrometry with Consumer-Quality CMOS Cameras

Abstract

Many modern spectrometric instruments use diode arrays, charge-coupled arrays, or CMOS cameras for detection and measurement. As portable or point-of-use instruments are desirable, one would expect that instruments using the cameras in cellular telephones and tablet computers would be the basis of numerous instruments. However, no mass market for such devices has yet developed. The difficulties in using megapixel CMOS cameras for scientific measurements are discussed, and promising avenues for instrument development reviewed. Inexpensive alternatives to use of the built-in camera are also mentioned, as the long-term question is whether it is better to overcome the constraints of CMOS cameras or to bypass them.

Stacked, Mutually Rotated Diffraction Gratings as Enablers of Portable Visible Spectrometry

“…The grating stacks described in this paper are an outgrowth of a teaching spectrometer previously described. 4,12–16 It was obvious from the start that cameras in cellular telephones would be a widely available array detector. Nevertheless, we have found that a barrier to wide adoption of such ubiquitous cameras is the firmware so useful for generating quality snapshots, independent of illumination.…”