An optical detection device image is disclosed that allows fast
measurements using near-field light at high resolution and high
efficiency but without necessity of position alignment of an optical
fiber probe. The optical detection device includes an optical fiber probe
having a core for propagating light with an optical probe being formed at
a front end of the core; a movement control unit to move the optical
fiber probe to approach or depart from a sample; and a detection unit to
detect light from the sample surface, wherein on the front end surface of
the core of the optical probe, there are a first exit section on a
peripheral side for emitting propagating light and a second exit section
for seeping out the near-field light, the first exit section and the
second exit section are formed in a concentric manner, and the tilt angle
of the first exit section is different from the tilt angle of the second
exit section.