A Raman imaging system which combined a hollow fiber bundle and a direct imaging technique was constructed for
high-speed endoscopic Raman imaging. The hollow fiber bundle is fabricated by depositing a silver thin film on the
inner surface of pre-drawn glass capillary bundle. It performs as a fiber optic probe which transmits a Raman image with
high signal-to-noise ratio because the propagating light is confined into the air core inducing little light scattering. The
field of view on the sample is uniformly irradiated by the excitation laser light via the probe. The back-scattered image is
collected by the probe and captured directly by an image sensor. A pair of thin film tunable filters is used to select target
Raman band. This imaging system enables flexible and high-speed Raman imaging of biological tissues.