IR MPD CDF<SUB>3</SUB> in two-frequency IR fields

The effectiveness of various sets of laser frequencies was analyzed for two-frequency MPD of CDF3 molecule at the different pressures of buffer gas. It was shown that MPD yield increased compared to either single-frequency or two adjacent frequencies irradiation

Fundamental Limits of the Dispersion of the Two-Photon Absorption Cross-Section

Javier Perez Moreno and Mark G. Kuzyk, J. Chem. Phys. 123, 194101 (2005). (13 pages) We rigorously apply the sum rules to the sum-over-states expression to calculate the fundamental limits of the dispersion of the two-photon absorption cross-section. A comparison of the theory with the data suggests that the truncated sum rules in the three-level model give a reasonable fundamental limit. Our ansatz that the two photon absorption cross-section near the limit must have only three dominant statesis is supported by a rigorous analytical calculation that the resonant term gets smaller as more states are added. We also find that the contributions of the non-explicitly resonant terms can not be neglected when analyzing real molecules with many excited states, even near resonance. However, puzzling as it may be, extrapolating an off-resonant result to resonance using only the resonant term of the three-level model is shown to be consistent with the exact result. In addition, the off-resonant approximation is shown to scale logarithmically when compared with the full three-level model. This scaling can be used to simplify the analysis of measurements. We find that existing molecules are still far from the fundamental limit; so, there is room for improvement. But, reaching the fundamental limit would require precise control of the energy-level spacing, independently of the transition dipole moments -- a task that does not appear possible using today's synthetic approaches. So, we present alternative methods that can still lead to substantial improvements which only require the control of the transition moment to the first excited state. While it is best to normalize measured two photon absorption cross-sections to the fundamental limits when comparing molecules, we show that simply dividing by the square of the number of electrons per molecule yields a good metric for comparison

Performance characteristics of a Nd: glass laser amplifier from fluorescence emission studies

The dependence of cavity transfer efficiency of a Nd: glass laser amplifier on flashlamp current density is obtained from the analysis of amplified fluorescence. The cavity transfer efficiency decreases as the current density through the flashlamps is increased. The use of the fluorescence method in optimizing the flashlamp pulse duration for achieving maximum gain in the amplifier is illustrated

Current-limited capacitor charging power supply for spark-gap-driven high repetition rate laser pulser

A short-circuit protected capacitor charging scheme for a spark-gap driven high repetition rate laser pulser is described. The possibility of using this scheme with a thyratron driven laser pulser is also discussed

Access to health services among slum dwellers in an industrial township and surrounding rural areas: A rapid epidemiological assessment

Context: The biggest challenge in implementing the primary health care principles is of equitable distribution of health care to all. The rural masses and urban slum dwellers are most vulnerable to lack of access to health care. Aim: To study access to health services among slum dwellers and rural population. Setting and Design: A cross-sectional survey in an urban slum and surrounding rural areas in field practice area of a medical college. Materials and Methods: Structured instrument along with qualitative techniques such as focus group discussions, were used to collect information on access and utilization of health services from 865 individuals of both sexes and all ages selected from urban slums, villages, and indoor and outdoor patients. Access to basic determinants of good health such as housing, water, and sanitation was also elicited. Besides, health needs based on self-reported disease conditions were compiled. Results: More than 50% of respondents were living in poor housing and insanitary conditions. Besides the burden of communicable diseases and malnutrition (especially in children), risk of lifestyle diseases as evidenced by high Body mass index in 25% of adults surveyed was found. Private medical practitioners were more accessible than government facilities. More than 60% sought treatment from private medical facilities for their own ailments (for sickness in children this proportion was 74%). People who visited government facilities were more dissatisfied with the services (30.88%) than those who visited private facilities (18.31%). This difference was significant (OR=1.99, 95% confidence interval 1.40 to 2.88; χ2 =15.95, df=1, P=0.007). The main barriers to health care identified were waiting time long, affordability, poor quality of care, distance, and attitude of health workers. Conclusion: The underprivileged in India continue to have poor access to basic determinants of good health as well as to curative services from government sources during illness