A PHOTON COUNTER AND PULSE-TRAIN GENERATOR INTERFACE FOR A PERSONAL-COMPUTER IN PULSE OPTICALLY DETECTED MAGNETIC-RESONANCE

The decay of coherently prepared excited triplet state can be observed by pulse optically detected magnetic resonance (ODMR). Analysis of th is data yields important information about the various relaxation path ways open to a molecule in a given environment. Pulse ODMR requires sh orter pulses with higher resolution than those used in pulse nuclear m agnetic resonance. Programmable pulse train generators are commerciall y available, but they can be costly. In this article, a fully programm able photon counter-pulse train generator interface is described which has the required resolution and speed. The interface cards occupy two slots of a personal computer and are based on advanced Shottky transi stor-transistor logic series of logic circuits. This inexpensive, yet highly flexible apparatus for use in pulse ODMR, can be adapted for ot her applications, such as pulse magnetic resonance and photon counting . In addition, the modular design allows easy expansion to multichanne l pulse or photon counting and to the generation of even the most imag inative pulse sequences.