Compact interferometers for chemical and biological agent detection
Manning Applied Technology is developing a series of compact and rugged interferometers with many applications, including chemical and biological agent detection. A nutating prism interferometer features high throughput, very rapid-scan capability and resistance to vibration. A novel multiplex Fabry-Perot interferometric spectrometer is especially compact and efficient, transferring about twice the modulated optical power to a detector, compared to a Michelson interferometer of equal volume. The bilithic interferometer features high throughput, intrinsic tilt compensation and compact size with the potential for high resolution measurements. For all of these interferometer geometries, digital signal processing (DSP) hardware and software are used to enhance the performance and allow rapid processing of data, including chemometric discrimination. Enhancements to system performance provided by DSP include application of Brault's data processing approach, frequency stabilization of a miniature solid state reference laser and computational correction of tilt errors. A key advantage of the DSP enhancements is compensation for non-ideal behavior of optical hardware. Many of the novel instruments described herein employ intrinsic optic tilt compensation. Either type of tilt compensation provides greater photometric accuracy and stability. Preliminary NESR characterization is reported for two of the instruments.