Laser & Light Emitting Diodes ••••
Laser and light emitting diodes (LEDs) are an exciting alternative to traditional lamps; they are bright, stable, and compact light sources. The LED and laser diode modules offered for K2T, PC1T, ChronosFDT, and PhoenixT SLM upgrade are easily interchangeable. Laser diodes can be modulated to high frequency and allow measurement of picosecond lifetimes. Frequency responses up to 600 MHz can be obtained on an ISS spectrometer using laser diodes and a photomultiplier tube (PMT) and up to 1 GHz using a microchannel plate (MCP) detector.
Xenon Arc Lamp ••••
The standard lamp utilized in ISS spectrofluorometers is a 300 W ceramic-design high-pressure xenon arc lamp. The design of the lamp is such that the light is entirely emitted in a narrow cone at an angle of about 10° around the optical axis. A condenser lens placed in front of the lamp easily collects almost all the light produced by the lamp and focuses it onto the entrance slit of the excitation monochromator. About 90% of the total light emitted is collected, and that is about 270 W of optical power! The lamp has a lifetime of approximately 2,500 hours and is easily replaced in minutes with the pre-aligned mechanical holder of the lamp housing.