An ophthalmic imaging apparatus that captures a tomographic image of an subject's eye based on light obtained by combining a return light with a reference light, the return light being from the subject's eye when irradiated with a measurement light, the reference light corresponding to the measurement light includes a first optical fiber disposed in an optical path of the reference light and including a light guide portion for guiding the reference light, and a second optical fiber disposed in an optical path of the measurement light and including a light guide portion for guiding the measurement light, wherein a diameter of each of the light guide portions of ejection ends of the first optical fiber and the second optical fiber is larger than a diameter of a light guide portion in a position different from a position of each of the ejection ends.

An apparatus comprising means for: causing illumination of different areas of a sample with an optical frequency imaging beam at different positions at different times, wherein adjacent positions are configured to cause the corresponding areas to at least partially overlap;receiving signals indicative of back-scattering of the optical frequency imaging beam from the sample at the different times; and processing the received signals to obtain an image of the sample, wherein processing the received signals compensates for phase variations between the different positions at the different times using a matched filter derived from a scattering model of the sample.

A reference signal having a known induced optical delay is used for phase stabilization of optical coherence tomography (OCT) interferograms, and for correcting sampling differences within OCT interferograms, in single mode and multimodal OCT systems. The reference signal can then be used to the measure time shift or sample clock period shifts induced in the interferogram signal by the OCT system. A corresponding OCT interferogram signal can then be corrected to remove the shift induced by the system based on the determination.

An optical coherence analysis system uses a laser swept source that is constrained to operate in a stable mode locked condition by modulating a drive current to the semiconductor optical amplifier as function of wavelength or synchronously with the drive voltage of the laser's tunable element based on stability map for the laser.

Disclosed herein are configurations for fiber optic endoscopes employing fixed distal optics and multicore optical fiber.

A frequency swept laser source for TEFD-OCT imaging includes an integrated clock subsystem on the optical bench with the laser source. The clock subsystem generates frequency clock signals as the optical signal is tuned over the scan band. Preferably the laser source further includes a cavity extender in its optical cavity between a tunable filter and gain medium to increase an optical distance between the tunable filter and the gain medium in order to control the location of laser intensity pattern noise. The laser also includes a fiber stub that allows for control over the cavity length while also controlling birefringence in the cavity.

A swept source OCT system and related method are disclosed. The system comprises a control device for operating a tunable light source in response to an electronic sweep control signal such that the tunable light source carries out wave length sweeps with a repetition rate f.sub.sweep, which depends on the frequency of the sweep control signal. The system further comprises a detection device for the time-resolved detection of an interference signal from a sample beam and a reference beam with the help of a detection cycle signal. The sweep control signal and the detection cycle signal are phase-locked, or means for creating a signal or signal sequence are provided, said signal or signal sequence being characterising for the frequency relationship and/or the relative phase position of the sweep control signal and detection cycle signal.

Length metrology apparatuses and methods are disclosed for measuring both specular and non-specular surfaces with high accuracy and precision, and with suppressed phase induced distance errors. In one embodiment, a system includes a laser source exhibiting a first and second laser outputs with optical frequencies that are modulated linearly over large frequency ranges. The system further includes calibration and signal processing portions configured to determine a calibrated distance to at least one sample.

Embodiments herein include swept-source interferometric imaging systems employing arbitrary sweep patterns in which a swept-source is swept over a continuous spectral range where the variation of wavelength over time is noncontinuous. Embodiments include sweep patterns that result in reduction of signals from moving scatterers and where the sweep is synchronized with the dead time of the camera.

A digital measuring device implemented on a photonic integrated circuit, the digital measuring device including a tunable laser source implemented on the photonic integrated circuit configured to sweep over a frequency range to provide multi-wavelength light, a first waveguide structure implemented on the photonic integrated circuit configured to direct a first portion of light from the laser source at a moving object and receive light reflected from the moving object, a second waveguide structure implemented on the photonic integrated circuit configured to combine a second portion of light from the laser source with the light reflected from the moving object to produce a measurement beam, and a first detector implemented on the photonic integrated circuit configured to detect intensity values of the measurement beam to measure a distance between the digital measuring device and the moving object.