Abstract: A first measuring light beam of wavelength &lgr;1 equal to a wavelength at the isosbestic point between oxyhemoglobin and deoxyhemoglobin and a second measuring light beam of wavelength &lgr;2 differing from the first measuring light beam are incident on the same part of a subject such as a human finger and scan the subject by using an X-Y stage movable in X and Y directions. The first measuring light beam branches into two light beams. One of the two light beams is subjected to a frequency shift by a frequency shifter, while the other is transmitted through the subject. Thereafter, the two light beams are synthesized and a beat component of the synthesized first measuring light beam is detected by a first signal detection section. The first signal detection section outputs a first beat-component detection signal. For the second measuring light beam, a second beat-component detection signal is output in the same manner as the first measuring light beam.

Abstract: A light source device for use in an image capturing device such as an endoscope capable of reducing size and cost, and preventing heat generation at an illuminated position. An illumination unit of the endoscope includes LED light sources for emitting ultraviolet light, fluorescent fibers for generating red, green and blue light respectively by irradiation of the ultraviolet light, a sampling light source, and an excitation light source. Upon capturing a normal image, the ultraviolet light is emitted sequentially from the LED light sources to cause the fluorescent fibers to generate the red, green and blue light. The light of each color is passed through a light guide and irradiated on an observation area of a living body. Thereafter, reflected images attributable to the light of each color are captured with a CCD image capturing element of a charge multiplying type, and captured images are displayed on a monitor.

Abstract: An compact imaging apparatus having an OCT function is provided. An image formed of the illuminating-light reflected from a examination area is displayed on a monitor. A signal-light for obtaining an optical tomographic image is guided in a fiber through an insertion portion and projected onto a living tissue measurement area by an illuminating lens. The measurement area is scanned with the signal-light by a Piezo actuator moving the output face of the fiber. An OCT obtaining-portion obtains and displays on a monitor an optical tomographic image by using the interference caused by the signal-light reflected from the measurement area and a reference-light. By performing the scanning with the signal-light using an image-obtaining lens, the need to insert a probe for obtaining an optical tomographic image through a forceps port is eliminated. Therefore, the number of required forceps ports is reduced, and the insertion portion can be made thin.

Abstract: An endoscope apparatus that has an OCT function and can efficiently obtain an optical tomographic image is provided. An image of an area within a body cavity is displayed on a monitor, and an operator uses a pen-type input to specify a point thereon. An aiming-light is projected onto the body cavity and displayed on said monitor as a bright point, and a coated tube of an OCT probe is slid and rotated by a scanning controller so as to align the aiming-light with the point. A scanning-area setting means sets a ring shaped scanning area when the aiming-light and point are aligned. The scanning area is scanned with a signal-light, and an optical tomographic image is obtained and displayed on a monitor. An optical tomographic image can be efficiently and expediently obtained without the need to manually direct the irradiation position of the signal-light to a desired scanning area.

Abstract: A blood vessel imaging system includes a measuring light source which emits a measuring light beam. An optical heterodyne detection system consists of an optical system which splits the measuring light beam into a first light beam traveling to impinge upon an 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 detector which detects beat components of the combined light beam. A band-pass filter detects, out of the beat component detection signal output from the beat component detector, off-centered components in a frequency band deviated from the center frequency of the beat component detection signal by a predetermined width.

Abstract: An apparatus for obtaining a cellular image to be used in performing a test for pathology of the sentinel lymph node, which is the first lymph node a cancer metastasizes to. The gamma radiation emitted from a near-infrared fluorescent colorant injected in advance into the vicinity of a tumor is detected by use of a gamma-probe. A fiber coupler separates the low-coherence light emitted from the light source of an OCT portion (Optical Coherence Tomography) into a signal-light to be projected onto the sentinel lymph node and a reference-light whose wavelength is slightly shifted. The signal-light is projected onto the sentinel lymph node, and interference is caused between the signal-light reflected from a predetermined depth within the sentinel lymph node and the reference-light. A balance differential detector measures the intensity of the interference-light, and a cellular level ultra high-resolution optical tomographic image of the sentinel lymph node is obtained.

Abstract: A fiber coupler separates, the low-coherence light emitted from a light source into a signal-light to be projected onto a target subject and a reference-light whose wavelength is shifted by a Piezo element, and combines the signal-light reflected from a predetermined depth within the target subject with the reference-light. A balance differential detector detects the signal strength of the interference-light after said combining, and said signal is processed by the signal processor; whereby an optical tomographic image of the target subject is obtained, and output to a monitor and to the diagnostic data output portion. The diagnostic data output portion performs pattern-matching between the optical tomographic image of the target subject and the pattern of a prerecorded standard optical tomographic image obtained of a normal tissue. If the two patterns substantially match, that the target subject is in the normal state is output to the monitor and displayed.

Abstract: A dynamic change detecting apparatus allows canceling the influence of environmental change or an individual difference between a plurality of laser elements so as to perform a stable detection.

Abstract: An optical tomograph obtains a tomogram of an object by dividing a low coherence light beam into a signal light beam and a reference light beam, shifting the frequency of at least one of the signal light beam and the reference light beam so that the signal light beam and the reference light beam becomes different from each other in frequency, causing the signal light beam to impinge upon the object, causing the signal light reflected at a predetermined depth of the object to interfere with the reference light beam, and measuring the intensity of the obtained interference light. A light amplifier amplifies the reflected signal light.

Abstract: Amplified spontaneous emission light, which is low coherence light radiated out from an optical fiber doped with a light emitting material when excitation energy is applied to the optical fiber, is divided into signal light and reference light. A frequency of the reference light is shifted to a frequency slightly different from the frequency of the signal light. A tomographic image of a measuring site is acquired from an intensity of interference light formed by the signal light reflected from the measuring site and the reference light.

Abstract: A dynamic change detecting apparatus permits selection of a combination condition of various detection sensitivities and dynamic ranges.

Abstract: In an optical coherence tomography apparatus: low-coherence light from a light source is split into signal light and reference light; at least one of the frequencies of the signal light and the reference light is shifted so as to produce a predetermined frequency difference between the frequencies; the reference light and a portion of the signal light reflected from the object are optically multiplexed so as to produce interference light; and the optical intensity of the interference light is detected in order to obtain a tomographic image of the object. In the light source, the pulse width of pulsed light emitted from a pulsed light source unit is reduced by an optical-waveguide structure. The optical-waveguide structure is made of a material having a normal dispersion characteristic, and includes a structure which realizes an anomalous dispersion characteristic so as to reduce the pulse width of the pulsed light.

Abstract: A low coherence light beam is irradiated to the eyeball. A backward scattered light beam, which is reflected from each depth position in the eyeball, and a reference light beam, which is reflected from a mirror capable of moving, are caused to interfere with each other. A first backward scattered light beam, which comes from the interface between the cornea and the anterior aqueous chamber, and a second backward scattered light beam, which comes from the interface between the anterior aqueous chamber and the crystalline lens, are thus separated accurately from each other. An optical absorbance of the anterior aqueous chamber (the aqueous humor) is calculated from the intensities of the two backward scattered light beams. Each of a plurality of low coherence light beams having different wavelengths is irradiated to the eyeball, and the aforesaid operation is repeated. The concentration of glucose in the aqueous humor is measured by utilizing near-infrared spectroscopy.

Abstract: A low coherence light beam is irradiated to the eyeball. A backward scattered light beam, which is reflected from each depth position in the eyeball, and a reference light beam, which is reflected from a mirror capable of moving, are caused to interfere with each other. A first backward scattered light beam, which comes from the interface between the cornea and the anterior aqueous chamber, and a second backward scattered light beam, which comes from the interface between the anterior aqueous chamber and the crystalline lens, are thus separated accurately from each other. An optical absorbance of the anterior aqueous chamber (the aqueous humor) is calculated from the intensities of the two backward scattered light beams. Each of a plurality of low coherence light beams having different wavelengths is irradiated to the eyeball, and the aforesaid operation is repeated. The concentration of glucose in the aqueous humor is measured by utilizing near-infrared spectroscopy.

Abstract: A low coherence light beam is irradiated to the eyeball. A backward scattered light beam, which is reflected from each depth position in the eyeball, and a reference light beam, which is reflected from a mirror capable of moving, are caused to interfere with each other. A first backward scattered light beam, which comes from the interface between the cornea and the anterior aqueous chamber, and a second backward scattered light beam, which comes from the interface between the anterior aqueous chamber and the crystalline lens, are thus separated accurately from each other. An optical absorbance of the anterior aqueous chamber (the aqueous humor) is calculated from the intensities of the two backward scattered light beams. Each of a plurality of low coherence light beams having different wavelengths is irradiated to the eyeball, and the aforesaid operation is repeated. The concentration of glucose in the aqueous humor is measured by utilizing near-infrared spectroscopy.

Abstract: A deep portion visualizing endoscope comprises a flexible fiber bundle, into which a laser beam produced by a frequency-sweep single frequency laser beam source is entered. The laser beam is irradiated from a radiating end of the fiber bundle to the region inside of a sample to be viewed, and is reflected from reflection planes of the sample. The reflected laser beam interferes with a laser beam, which has been split from the laser beam before being reflected from the reflection planes and which has traveled by a predetermined optical path length, and an image signal is thereby obtained. The image signal is composed of a plurality of difference-frequency beat signals such that the frequencies, at which the signal intensities repeatedly become high and low, may vary in accordance with the difference between depths of the reflection planes from the inner surface of the sample.

Abstract: A deep portion visualizing endoscope comprises a flexible fiber bundle, into which a laser beam produced by a frequency-sweep single frequency laser beam source is entered. The laser beam is irradiated from a radiating end of the fiber bundle to the region inside of a sample to be viewed, and is reflected from reflection planes of the sample. The reflected laser beam interferes with a laser beam, which has been split from the laser beam before being reflected from the reflection planes and which has traveled by a predetermined optical path length, and an image signal is thereby obtained. The image signal is composed of a plurality of difference-frequency beat signals such that the frequencies, at which the signal intensities repeatedly become high and low, may vary in accordance with the difference between depths of the reflection planes from the inner surface of the sample.

Abstract: A deep portion visualizing endoscope comprises a flexible fiber bundle, into which a laser beam produced by a frequency-sweep single frequency laser beam source is entered. The laser beam is irradiated from a radiating end of the fiber bundle to the region inside of a sample to be viewed, and is reflected from reflection planes of the sample. The reflected laser beam interferes with a laser beam, which has been split from the laser beam before being reflected from the reflection planes and which has traveled by a predetermined optical path length, and an image signal is thereby obtained. The image signal is composed of a plurality of difference-frequency beat signals such that the frequencies, at which the signal intensities repeatedly become high and low, may vary in accordance with the difference between depths of the reflection planes from the inner surface of the sample.

Abstract: A low coherence light beam is split into first and second light beams, and the frequency of the first light beam is shifted. The first and second light beams are then combined with each other at a position at which the optical path difference between the two light beams is larger than the coherence length of the low coherence light beam. The combined light beam is guided to a position in the vicinity of a medium having light scattering properties and split into a third light beam, which travels reversely to the direction of travel of the combined light beam, and a fourth light beam, which is irradiated to the medium. A light beam scattered backwardly from a predetermined depth in the medium is caused to interfere with the third light beam, and the intensity of the resulting interference light beam is detected.

Abstract: A superheterodyne split-beam system is used to measure the refractive index distribution associated with a light scattering medium. Initially, a coherent light beam is split into a first reference light beam and a second light beam. The second light beam is passed through a light scattering medium. Scattered and unscattered portions of the second light beam are separated using the characteristic that the scattered light travels by a longer optical path length than the unscattered light. The first light beam is recombined with the unscattered light beam, and the associated optical path difference is measured. Using the difference between the calculated path difference and a predetermined reference path difference, as well as the thickness of the scattering medium, refractive indices are measured. The use of a photodetector array allows for determining a distribution of the refractive indexes of the inclusions at various portions of the medium.