High-brightness lamps

The two traces in Figure 4 prove the point. Each represents the absorption from 10 p.p.m. silicon, run under identical conditions, with only one difference Trace A used an ordinary silicon hollow-cathode lamp, (vintage 1966), while Trace B was made with a much superior High-Brightness lamp. The sensitivity (in p.p.m./l%) is the same for the two traces, but the signal-to-noise ratios, and therefore the detection limits, are clearly very different indeed. 

High-brightness lamps, which were developed at CSIRO (Commonwealth Scientific and Industrial Research Organisation, Australia), are based on standard hollow cathodes, but contain a pair of auxiliary electrodes (13). In ordinary hollow cathode lamps, not all the atoms which are sputtered off the cathode are excited. Since only the excited... 

High-brightness LEDs are expected to operate at high optical power densities, with junction temperatures reaching -200° C, a wide range of external temperatures, and humidity levels that could exceed 90% relative humidity (RH). Therefore, it is of critical importance to investigate the operational limits of any LED phosphor and to develop techniques and materials that will improve the phosphor and LED lamp performance under extreme operating conditions. 

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