Blood vessel imaging system

A blood vessel imaging system comprising

• a measuring light source which emits a measuring light beam,
• a scanning means which causes the measuring light beam to scan an organism,
• an optical heterodyne detection system consisting of an optical system which splits the measuring light beam upstream of the organism into a first light beam traveling to impinge upon the organism and a second light beam traveling not to impinge upon the organism and combines the second light beam with the first beam emanating from the organism into a combined light beam, a frequency shifter which causes the first and second light beams to have frequencies different from each other, and a beat component detecting means which detects beat components of the combined light beam,
• a first intensity detecting means which detects the intensity of center frequency components of the beat component detection signal output from the beat component detecting means,
• a second intensity detecting means which detects the intensity of off-centered components of the beat component detection signal in a frequency band deviated from the center frequency of the beat component detection signal by a predetermined width, and
• an image signal generating means which generates an image signal on the basis of the ratio of the intensity of the off-centered components of the beat component detection signal to the intensity of the center frequency components of the beat component detection signal.

A blood vessel imaging system comprising

• a measuring light source which emits a measuring light beam,
• a scanning means which causes the measuring light beam to scan an organism,
• an optical heterodyne detection system consisting of an optical system which splits the measuring light beam upstream of the organism into a first light beam traveling to impinge upon the organism and a second light beam traveling not to impinge upon the organism and combines the second light beam with the first beam emanating from the organism into a combined light beam, a frequency shifter which causes the first and second light beams to have frequencies different from each other, and a beat component detecting means which detects beat components of the combined light beam,
• a spectrum analysis means which obtains the spectrum of the beat component detection signal output from the beat component detecting means, and
• an image signal generating means which generates an image signal on the basis of a spectral width between two frequencies at which the intensity of the beat component detection signal takes a predetermined value with respect to the intensity of the center frequency components.