Jamin interferometer

E. Mach and his son L. Mach were the first to apply an interferometer to ballistics (Refs 3 4). They modified the Jamin Interferometer and used it to determine the densities of air near a projectile. A schematic arrangement of their apparatus is given in. Ref 4, p 274, fig 105 and in Ref 10, p 1360. Zehnder (Ref 2) modified Mach s apparatus and the so-called Mach-Zehnder apparatus is still used... 

The probe beam is split by the plane-parallel plate Pll into two beams. One beam passes through that region of the absorbing sample that is saturated by the pump beam the other passes through an unsaturated region of the same sample cell. The two beams are recombined by a second plane-parallel plate P12. The two carefully aligned parallel plates form a Jamin interferometer [273], which can be adjusted by a piezoelement in such a way that without the saturating pump beam the two probe waves with intensities I and h interfere destructively. 

The sensitivity of the saturated interference technique is comparable to that of polarization spectroscopy. While the latter can be applied only to transitions from levels with a rotational quantum number / > 1, the former works also for 7=0. An experimental drawback may be the critical alignment of the Jamin interferometer and its stability during the measurements. 

While Michelson interferometers are typically used to measure distance differences between the two reflecting surfaces, there are many other configurations. Some examples are the Mach-Zehnder and Jamin interferometers, in which two beams are... 

Figure 5.26. Jamin interferometer, where the OPD is introduced by rotating the rocking mirror. (Reproduced from [32], by permission of John Wiley Sons copyright 1965.)...

Many other interferometers have been described in the literature (see references). Among these are the Fresnel, Fabry P ot, Jamin, Rayleight, Michelson and Mach-Zehnder interferometers. 

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