Fox-Smith selector

This illustrates that the MI can be regarded either as a wavelength-dependent filter for the transmitted light, or as a wavelength-selective reflector. In the latter function it is often used for mode selection in lasers (Fox-Smith selector. Sect. 5.4.3). 

Fig. 5.37a,b. Mode selection with a Fox-Smith selector (a) experimental setup (b) maximum reflectivity and inverted finesse /F of the Michelson-type reflector as a function of the reflectivity Rbs of the beam splitter for R2 = Rs= 0.99 and Abs = 0.5%... 

In a more detailed discussion the absorption losses of the beam splitter BS cannot be neglected, since they cause the maximum reflectance R of the Fox-Smith cavity to be less than 1. Similar to the derivation of (4.76), the reflectance of the Fox-Smith selector, which acts as a wavelength-selecting laser reflector, can be calculated to be [5.53]... 

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