NYU and Hinds collaborate to develop a Mueller matrix polarimeter for chiroptical spectroscopy of crystals.
Hillsboro, Oregon, September 20, 2011 – Hinds Instruments, a leading global supplier of photoelastic modulators (PEMs), along with New York University today announced the awarding of an NSF-sponsored Grant Opportunity for Academic Liason with Industry (GOALI). The grant is entitled, “GOALI: Chiroptical Spectroscopy” and is intended to fund the development of an instrument that will determine chiroptical properties of crystals. The instrument design will entail the use of four photoelastic modulators (PEMs), the heart of Hinds polarization measurement technology.
The principal investigators on the grant are Bart Kahr, Ph.D from the Chemistry Department at New York University and Bob Wang, Ph.D. from Hinds Instruments. The grant provides for a postdoctoral fellow, John Freudenthal, to work for the next two years at the Hinds facility in Hillsboro, Oregon. Freudenthal will receive his PhD at Bart Kahr’s NYU laboratory this autumn. The award will also provide support to Dr. Oriol Arteaga, (PhD Barcelona) who will be carrying out complementary work in New York. He brings considerable experience working with PEMs. The award will provide support for frequent exchanges between the academic and industrial laboratories.
Chiroptical materials have traditionally been measured using a classical interpretation of optical rotation. In fact, the problem is more complicated than previously considered, and requires the measurement of several polarization producing properties, including linear birefringence (LB), linear dichroism (LD), circular birefringence (CB), and circular dichroism (CD). “To measure the optical activity along a general direction of a crystal one has to understand how the combination of LB and LD with CB and CD affect the polarization state of light,” according to Dr. Kahr.
The new Four-PEM Mueller matrix polarimeter will provide this information. The use of four PEMs will generate four polarization modulation frequencies, as well as many other frequencies derived from harmonic and combined frequencies of the PEMs. The demodulation and analysis of all of these many signals will provide much more information than simpler instruments that have been designed in the past. This will allow the determination of all the relevant polarization properties in crystals. Success of the project may enable others to more easily measure the chiroptical properties of molecular crystals and materials which may lead to new understanding in the field.
“We are excited about this opportunity! Our current Exicor® birefringence measurement systems are widely used in research and industry for measuring specific polarization properties. A polarimeter built with four PEMs will characterize all of the polarization properties of a sample instantaneously. This will provide scientists and investigators with a powerful new tool for their polarization research applications,” according to Dr. Wang.
Hinds Instruments, Inc. is the world leader in developing and supplying polarization modulation technology for a broad range of applications. With 40+ years of polarization modulation experience, Hinds Instruments PEM-based solutions are proven tools for laboratory and research applications. Hinds’ family of products includes modulators, Stokes polarimeters, Mueller matrix polarimeters, MOKE measurement systems and Exicor® birefringence measurement systems. For more information, please contact Hinds Instruments.