Waveguide-based single-pixel up-conversion infrared spectrometer

A periodically poled lithium niobate (PPLN) waveguide-based single-pixel up-conversion infrared spectrometer was demonstrated. Sum-frequency generation between a 1.5 micrometer band scanning pump laser and a 1.3 micrometer band signal generated visible radiation which was detected by a silicon single-photon detector. The noise equivalent power of the upconversion spectrometer was two-orders-of-magnitude lower than that of a commercial optical spectrum analyzer.Comment: 5 pages, 3 figure

Vibrational lifetimes and intramolecular energy randomisation of polyatomic molecules in liquids

Transient experiments with picosecond laser pulses give valuable information on the dynamic properties of polyatomic molecules in the electronic ground state. In small molecules the decay of vibrational energy occurs via individual lower energy states; in large molecules the experimental data support a statistical model

Resonant nonlinear spectroscopy in strong fields

A method is presented to describe multiple resonant nonlinear spectra in the presence of strong laser fields. The Liouville equation for the d. operator of the mol. system is transformed to a time-independent linear equation system. This can be easily solved rigorously by numerical methods or, after partitioning into a strong-field part and a perturbation, the soln. can be obtained anal. by a novel perturbative approach. The results account for power broadening. Rabi splitting of signals, and power-induced extra resonances, the latter being related to the pure dephasing-induced resonances in the weak-field limit. The method can be applied to a large no. of multiple resonant nonlinear spectroscopies, esp. CARS, CSRS, coherent Rayleigh scattering and sum- or difference-frequency generation

An Infrared Imaging Method for High-Throughput Combinatorial Investigation of Hydrogenation-Dehydrogenation and New Phase Formation of Thin Films

We have developed an infrared imaging setup enabling in situ infrared images to be acquired, and expanded on capabilities of an infrared imaging as a high-throughput screening technique, determination of a critical thickness of a Pd capping layer which significantly blocks infrared emission from below, enhancement of sensitivity to hydrogenation and dehydrogenation by normalizing raw infrared intensity of a Mg thin film to an inert reference, rapid and systematic screening of hydrogenation and dehydrogenation properties of a Mg–Ni composition spread covered by a thickness gradient Pd capping layer, and detection of formation of a Mg2Si phase in a Mg thin film on a thermally oxidized Si substrate during annealing

Rates of distress vocalizations in naive domestic chicks as an index of approach tendency to an imprinting stimulus

Naive chicks were exposed to an imprinting target, consisting of a bank of miniature flashing lights, under normal (100[deg]F) and reduced temperatures (75 and 57[deg]F). It was found that cold reliably evoked distress calls and that the cyclic presentations of the target substantially reduced distress calling when the target was present, relative to when it was absent. When later tested for approach tendencies to the target, clear differences between temperature groups did not emerge. Evidence was obtained, however, that chicks that showed the greatest reduction in distress calling in response to the presentation of the target under the cold conditions showed significantly greater approach tendencies in the subsequent tests.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33786/1/0000041.pd