No abstract

, H. 2006. Prediction of crude protein content in field peas using near infrared reflectance spectroscopy. Can. J. Plant Sci. 86: 157-159. A rapid, near-infrared spectroscopic method to predict the crude protein contents of 72 field pea lines grown in Saskatchewan, both whole seeds and ground samples, was established. Correlation coefficients between the laboratory and predicted values were 0.938 and 0.952 for whole seed and ground seed, respectively. Both methods developed are adequate to support our field pea breeding programme. Mots clés: Pois de grande culture, spectroscopie par réflectance dans le proche infrarouge, protéine brute Field pea (Pisum sativum L.) crops are utilized in both food and feed applications. In both cases, high protein content is desirable. Breeding programs produce thousands of lines a year, which are evaluated for agronomic and quality traits. Assessment of protein content by the Dumas combustion method is accurate but expensive, primarily due to the high initial cost of the equipment. A method for the rapid, inexpensive assessment of protein content would allow this trait to be more effectively evaluated in a breeding program.

Scattering-type scanning near-field optical microscopy (s-SNOM) enables infrared spectroscopy at 10− 20 nm spatial resolution through elastic light scattering. Coupled with an infrared light source, s-SNOM characterizes chemical compositions or probes nanoscale photonic phenomena on length scales 2 orders of magnitude below the diffraction limit. However, widespread use of s-SNOM as an analytical standard tool has been restrained to a large extent by the lack of a bright and affordable broadband light source.Here we present a turnkey thermal emitter based on a laserdriven plasma that offers incoherent radiation of a broader bandwidth (>1000 cm −1 ) and ∼40-fold higher brilliance than previous blackbody radiators in addition to a compact size and at a fraction of the cost of alternative coherent laser systems or synchrotrons. We demonstrate a nearly 1 order of magnitude increase in signal-to-noise in near-field spectra compared to existing incoherent emitters, which allows probing of not only inorganic materials and polaritonic systems but also various commonly used polymers despite their weak near-field optical response. The latter important representative of soft matter was previously inaccessible by table-top thermal radiators. s-SNOM combined with the laser-driven plasma will provide a widely accessible platform for infrared nanospectroscopy.

Phonon polaritons (PhPs) are quasiparticles created by coupling of photons to polar lattice vibrations. Previously, PhPs have been observed as both surface and volume confined waves. The dispersion of the polariton depends strongly on the nature of the material. Volume polaritons show asymptotic behavior near the longitudinal optical phonon frequency of the material, whereas surface polaritons instead approach the surface phonon frequency. Boron nitride nanotubes (BNNTs) were found to exhibit the dispersion of volume modes below the surface phonon frequency. However, around and above the surface phonon frequency, the behavior becomes that of a surface wave with an amplified near-field response. These findings improve our understanding of photonics within BNNTs and suggest potential applications that take advantage of the high fields and density of states in that spectral region.

Phonon polaritons (PhPs) offer extreme confinement of optical fields and strong dispersion in the mid-infrared spectral region. To study the propagation and interference of PhPs in a 1-D system, we employ scattering scanning near-field optical microscopy (s-SNOM), analytical, and computational techniques to describe the resonance behavior observed in boron nitride nanotubes (BNNTs). In BNNTs of a sufficiently small length, the reflected standing waves from both terminals strongly interfere with one another, leading to large constructive enhancement at select wavelengths through the Fabry−Peŕot interference. This 1-D nanoresonant behavior illustrates methods to increase and localize field strength at positions on a BNNT nanotube.