Abstract: Common path frequency domain optical coherence reflectometry/tomography devices include a portion of optical fiber with predetermined optical properties adapted for producing two eigen modes of the optical radiation propagating therethrough with a predetermined optical path length difference. The two replicas of the optical radiation outgoing from the portion of the optical fiber are then delivered to an associated sample by an optical fiber probe. The tip of the optical fiber serves as a reference reflector and also serves as a combining element that produces a combination optical radiation by combining an optical radiation returning from the associated sample with a reference optical radiation reflected from the reference reflector. The topology of the devices allows for registering a cross-polarized or a parallel-polarized component of the optical radiation reflected or backscattered from the associated sample.

Abstract: Polarization sensitive common path OCT/OCR devices are presented. Optical radiation from a source is converted into two cross-polarized replicas propagating therethrough with a predetermined optical path length difference. The two cross-polarized replicas are then delivered to an associated sample by a delivering device, which is, preferably, an optical fiber probe. A combination optical radiation is produced in at least one secondary interferometer by combining a corresponding portion of an optical radiation returning from the associated sample with a reference optical radiation reflected from a tip of an optical fiber of the optical fiber probe. Subject to a preset optical path length difference of the arms of the at least one secondary interferometer, a cross-polarized component, and/or a parallel-polarized component of the combined optical radiation, are selected. The topology of the devices allows for time domain, as well as for frequency domain registration.

Abstract: Polarization-sensitive optical coherence devices for obtaining birefringence information are presented. The polarization state of the optical radiation outgoing from the optical radiation source is controlled such that the polarization state of the optical radiation incident on a sample has a 45 degrees angle with respect to the anisotropy axis of the sample. A combination optical radiation is produced in a secondary interferometer by combining a sample portion with a reference portion of optical radiation reflected from a tip of an optical fiber of the optical fiber probe. Subject to a preset optical path length difference of the arms of the secondary interferometer, a cross-polarized, and/or a parallel-polarized component of the combined optical radiation, are selected. Time domain and frequency domain registration are provided. The performance of the device is substantially independent from the orientation of the optical fiber probe with respect to the sample.

Abstract: The developed device for studying an object ensures straightforward ultimate matching between the arms of an optical interferometer and therefore, high in-depth resolution when being used in clinical and industrial applications. According to the invention at least one arm of the optical interferometer of the device comprises at least one replaceable part with preset optical properties. The preset optical properties of the replaceable part of the one arm of the optical interferometer are determined by the optical properties of at least a part of the other arm of the optical interferometer, such as of the optical fiber probe. That makes it possible, for example, to supply the device with a kit of replaceable sets, which include an optical fiber probe and a replaceable part of the reference arm made of the same reel of optical fiber. Using these sets in clinical and industrial applications is most effective and does not call for highly qualified personnel.

Abstract: The invention presents modifications of a protector design for an optical fiber probe intended for studying an object. The object being studied can be a biological tissue, namely, a biological tissue of a living body, for example, an internal cavity of a living body. The invention ensures an effective optical contact between an end face of a distal part of the optical fiber probe and the object being studied. In a preferred embodiment the later is achieved by designing an inner surface of a protector window capable of forming a temporary adhesive contact with the end face of the distal part of the optical fiber probe under a pressure of an axial force exerted on the optical fiber probe placed inside a sheath. Herewith, an outer surface of the protector window is designed capable of forming a temporary adhesive contact with the object being studied under the pressure of the axial force exerted on the optical fiber probe placed inside the sheath.

Abstract: Common path frequency domain optical coherence reflectometry/tomography devices with an additional interferometer are suggested. The additional interferometer offset is adjusted such, that it is ether less than the reference offset, or exceeds the distance from the reference reflector to the distal boundary of the longitudinal range of interest. This adjustment allows for relieving the requirements to the spectral resolution of the frequency domain optical coherence reflectometry/tomography engine and/or speed of the data acquisition and processing system, and eliminates depth ambiguity problems. The new topology allows for including a phase or frequency modulator in an arm of the additional interferometer improving the signal-to-noise ratio of the devices. The modulator is also capable of substantially eliminating mirror ambiguity, DC artifacts, and autocorrelation artifacts. The interference signal is produced either in the interferometer or inside of the optical fiber probe leading to the sample.

Abstract: The present invention relates to an optical fiber magnetic scanning arrangement for a miniature optical fiber probe and can be applied for optical beam delivery in various optical imaging techniques. The arrangement is of the type where an optical fiber is rigidly fixed to a current conductor and serving as a flexible cantilever with a capability for the distal part of the optical fiber of being deflected in a direction substantially orthogonal to its own axis. New designs of the magnetic system are less critical to the shape and dimensional tolerances of scanner elements and assembly. These designs provide a potential for a less difficult assembly process and for further miniaturization. According to one aspect of the invention the permanent magnet system includes at least a first permanent magnet with a magnetization direction that is substantially aligned with the own axis of the optical fiber. The current conductor loop is placed adjacent to the one of the end faces of the first permanent magnet.

Abstract: The invention relates to studies of internal structures of objects with the aid of optical means. According to the invention an optical system (15) of the delivering device for low coherence optical radiation, in a particular embodiment, an optical fiber probe (8), includes at least two lens components (19), (20), which have a positive focal power and are positioned substantionally confocally. This ensures a constant propagation time for the low coherence optical radiation propagating from a given point of the transverse scanning surface (28) or (39) to a corresponding conjugate point of the image plane (22). That provides elimination of the transverse scanning related aberration of the optical path length for low coherence optical radiation directed towards the object (11) both for a flat transverse scanning surface (28) and for a transverse scanning surface (39) having a curvature.

Abstract: In a method for in vivo diagnostics of a biological tissue covered with epithelium an image of the biological tissue is acquired with the aid of a beam in the visible or near IR range directed towards a biological tissue by visualizing the intensity of optical radiation backscattered by the biological tissue. The basal membrane of said biological tissue, which separates the epithelium from an underlying stroma, is identified in the acquired image and diagnostics is performed on basis of the form of the basal membrane. For diagnostics of biological tissue lining the surface of cavities and internal organs of a patient a miniature optical fiber probe is inserted into the patient's cavity. The probe may be placed at a distal end of an endoscope instrumental channel.