A method for localization of a light source near the interface of two
media is described. The method is based on an optical analog of tunnel
effect when the radiation source is at the distance smaller than the
wavelength from the interface. Application of the tunnel effect permit
s to obtain high resolution. The developed method was used to determin
e the localization of a bacterial luminescent system. It has been foun
d that the sources of bioluminescence are located at thin subsurfase l
ager with width about 70 nm. This result is in favour of the periphera
l (periplasmatic or membrane) localization of the bacterial luminescen
t system. This method makes it possible to investigate processes pelat
ed to light radiation (luminescence, fluorescence and other optical pr
ocesses) in a thin surface layer of various biological and physical ob
jects.