Apparatus for detecting light scattered by a small particle (e.g., a blood
cell) irradiated by a light beam comprises one or more photodetectors and a plurality
of optical fibers that serve to optically couple the scattered light and the photodetector(s).
To enhance the efficiency of such optical coupling, a portion of each of the optical
fibers in the vicinity of its light-collecting end is supported so that its optical
axis extends towards the light-scattering source. By this arrangement, scattered
light enters each fiber from a direction substantially parallel to the fiber axis.
Preferably, the light-collecting ends of the optical fibers are supported on a
concave surface and so that the respective optical axes of the fibers converge
at a point representing the apparent position of the light-scattering source, taking
into account the refractive effects of an optical flow cell through which scattering
is detected. Preferably, both forward- and back-scattered light are detected by
the apparatus of the invention.
