98 



PROGRESS IN MICROSCOPY 



plates Lj and Lo, it could not be reached with a short-focus powerful 

 objective. The light emerging from the plate Lo is then taken over 

 by a half-sphere. The NEF ray proceeds in a glass of the same index 



K-rTTrrrrrrr, 

 I 



Fig. 3.4. Dyson interference microscope. 



Fig. 3.5. Basic diagram of the ray paths in Dyson interference microscope. 



as Ly and L> which is bounded by the reflecting sphere FA'F' (B centre). 

 The NEF ray is reflected at F on to this concave spherical mirror and 

 doubles back on itself to be reflected anew on to the semi-reflecting 

 surface .V3.Y3. It ends ultimately at A' symmetrically with B in relation 



