Laser opticoacoustic method for measurement of relative content of isotopes in molecules

A new method is suggested to measure relative content of isotopes in molecules with the help of laser spectrophones. A description and operating principle are presented of the experimental system based on the compensation measurement method with the use of the laser radiation emitted at two frequencies with periodic comparison of signals in two spectrophones. The results are given of experimental measurements of the variation in the ratio of 10B and 11B isotopes. The problem is discussed of the ultimate sensitivity of the suggested measurement method which makes it possible to measure the deviation of the isotopic content of the molecule from the standard one up to 10-4%, the laser power being about 1 W