The Monte Carlo method in the predetermination of a luminous intensity distribution

The Monte Carlo method is applied to the predetermination of a luminous intensity distribution in luminaire design. In this technique, the random travels of light quanta such as photons are statistically analyzed to obtain the luminous intensity distribution. That is, the behavior of many photons are determined using random numbers. The photon paths are traced until either they are absorbed by intercepting surfaces or until they are emitted outside the luminaire. Basic procedures of simulating photon emissions and photon reflections are described. These procedures together with photometric properties measured on elements composing a luminaire, are applied to predetermining the luminous intensity distribution of a luminaire composed of a fluorescent high pressure mercury lamp and a reflector with a blasted aluminum surface of revolution. It is revealed that approximately 106 trials are required to predetermine a luminous intensity distribution with a precision of 1%.