Time-Dependent Infrared Imaging

Three-wave and four-wave sum-frequency mixing has been used for conversion of radiation from the infrared to the visible, where photographic film can be used and photoelectric detectors offer the advantages of improved sensitivity and increased temporal resolution. Infrared up-conversion has been used for up-conversion of infrared images to the visible and for time-resolved studies of the rotational spectra of molecules formed in explosions, giving information as to the time dependence of the temperature. 

In their most recent study Eigenbrodt et al. reported a detailed investigation of carbon deposition on YSZ-Ni anodes operating in YSZ electrolyte based SOFC run on methanol and methane using in-situ near infrared imaging and Raman spectroscopy [162]. Time dependent Raman spectra collected from SOFC anodes which were held at OCP at 715 °C and exposed to methanol and methane are shown in Fig. 17(a) and (b) respectively. The characteristic D and G peaks of carbon are observed to appear for the anode exposed to methanol while only the G peak is observed for the anode exposed to methane. It is clear from the evolution of these peaks that carbon forms on the anode exposed to methanol much more quickly than that exposed to methane. This is emphasised in Fig. 17(c) where spectra were... 

Figure 15.14 Temporally resolved series of infrared images for a Thalassiosira weiss-flogii algal cell. Distributions of biochemically Important functional groups and time-dependent changes in the concentrations of several biochemical functional groups maintained in the flow cell. The images are obtained from data sets for one algal cell, collected at 0, 3, and 8h after exposure to medium containing a high concentration...

We have also demonstrated picosecond time-resolved TFD-IR imaging of the vibration relaxation of Rhodamine-6G in Arabidopsis thaliana roots, and found an abnormally long-lived component of vibrational relaxation in a cell. This may result from a site dependence of vibrational relaxation within whole cells. These results indicate the possible utility of the two-color super-resolution infrared microscope in mapping specific IR absorptions with high spatial resolution, and the observation of dynamics in a non-uniform environment, such as a cell. By using this infrared super-resolution microscope, we will be able to visualize the structure and reaction dynamics of molecules in a wide range of non-uniform environments. 

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