Short wavelength infrared frequency conversion in ultra-compact fiber device.

Linear and nonlinear characteristics of devices using millimeter-scale spools of highly nonlinear fiber are experimentally investigated within 2000-2400nm spectral range. Coils with radius larger than 3.5 mm indicate that macro-bending induced radiation loss is negligible up to 2400nm. Devices with smaller diameter coiling resulted in macro-bending losses that dominate over micro-bending losses beyond 2200nm. A tunable short-wave infrared source was constructed using a coin-sized fiber module to demonstrate an efficient nonlinear conversion from 1.26 to 2.2 microm.

Oral malodor in children and volatile sulfur compound-producing bacteria in saliva: preliminary microbiological investigation.

PURPOSE: This study examined and compared levels of salivary bacteria which produced volatile sulfur compounds (VSC) in young children with and without oral malodor. METHODS: Clinic populations of children aged two to seven years, whose parents presented with an unsolicited major complaint of oral malodor in their child (OM+), or aged-matched controls in whom oral malodor was not detected by parents (OM-), were investigated. Saliva specimens were cultured anaerobically on media that differentiated VSC+ bacteria. These were quantified and identified. Levels in OM+ and OM- children were compared and statistically analyzed. RESULTS: OM+ children harbored significantly higher levels of VSC+ isolates in saliva than OM- children (OM+ = 44% of total viable counts, TVC; OM- = 24% of TVC; P = 0.0083). Types of recovered bacterial species did not differ in the two groups, but levels of Prevotella oralis were significantly higher in OM+ children (P = 0.0001). Veillonella species followed by P. oralis were the predominant VSC+ isolates recovered in both populations. CONCLUSIONS: VSC+ salivary bacteria may differ both in type and quantity in young children with and without parent-perceived oral malodor.