Abstract:
An optical fiber magnetic scanning arrangement for a miniature optical fiber probe is provided for various optical imaging applications. The magnetic system includes a permanent magnet piece with a magnetization direction substantially orthogonal to the own axis of the optical fiber. The permanent magnet piece extends in a direction substantially aligned with the own axis of the optical fiber, wherein the current conductor loop is adjacent an inner surface of the permanent magnet piece. In another embodiment, the permanent magnet is of a hollow cylinder type with a radial magnetization direction. The permanent magnet cylinder extends in a direction substantially aligned with the own axis of the optical fiber, the current conductor loop being placed inside the permanent magnet cylinder. The designs provide a potential for further miniaturization.
Abstract:
Provided are common path frequency domain and time domain OCT systems and methods that use non-specular reference reflection for obtaining internal depth profiles and depth resolved images of samples. Further provided is a delivering device for optical radiation, preferably implemented as an optical fiber probe with a partially optically transparent non-specular reflector placed in the vicinity of an associated sample. High frequency fringes are substantially reduced and a stable power level of the reference reflection is provided over the lateral scanning range. The partially optically transparent non-specular reflector is implemented as a coating placed on the interior surface of the optical probe window including spots of a metal, or a dielectric coating, separated by elements of another coating or just spaces of a clean substrate. In an alternative embodiment, the scattering elements are made 3-dimentional, having, for example, a spherical shape.
Abstract:
An optical measurement device calibration tool includes an optical probe suitable for calibrating various optical imaging devices, for example, low coherence reflectometers and optical coherence tomography devices. In a preferred embodiment the calibration tool comprises a container containing a calibration substance with stable optical scattering and absorption properties. The calibration substance includes a gel, paste or grease substance and is covered a protective seal, which is at least partially transparent providing optical contact between the optical probe and the calibration substance. The protective seal is covered with a viscous complementary material. Another protective seal made at least partially removable is placed above the viscous complementary material and may serve as a cover for the container. The calibration tool maintains the advantages of calibration tools using liquids and solid states as calibration substance and is more cost-effective and more convenient for calibrating optical measuring devices such as in medical applications.
Abstract:
In common path time domain OCT/OCR devices optical radiation from a source is first split into two replicas, which are then delivered to an associated sample by an optical fiber probe. The tip of the optical fiber probe 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 eliminates the necessity of using Faraday mirrors, and also allows for registering a cross-polarized component of the optical radiation reflected or backscattered from the associated sample, as well as a parallel-polarized component.
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:
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:
A forward looking optical fiber probe includes an optoelectronic lateral scanner that provides circular scanning using a single pass-through optical motor and a single rotating deflector. The optical fiber is kept stationary while circular scanning is provided by an optically transparent rotating deflector intersected by the optical radiation. The arrangement allows for hermetically sealing the optical fiber probe for disinfection, sterilization and clinical use in a clean environment in general. The design is suited to be used in a miniature forward looking optical fiber probe and has a potential for advanced manufacturing and assembling process.
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.