A signal control module integrated to a low coherence interferometry including a one-dimensional (1D) array image sensor is provided. The signal control module includes an image acquisition controller and a signal controller. The image acquisition controller sends a 1D image acquisition control signal. The signal controller sends a two-dimensional (2D) image acquisition control signal, wherein the 1D and 2D image acquisition control signals are synchronized with each other. The 1D array image sensor captures 1D image information of an object-to-be-tested at different positions along a direction according to the 1D and 2D image acquisition control signals. The 1D image information constitutes 2D image information. Furthermore, a low coherence interferometry is provided.

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.

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.

An optical imaging system includes an optical radiation source (410, 510), a frequency clock module outputting frequency clock signals (420), an optical interferometer (430), a data acquisition (DAQ) device (440) triggered by the frequency clock signals, and a computer (450) to perform multi-dimensional optical imaging of the samples. The frequency clock signals are processed by software or hardware to produce a record containing frequency-time relationship of the optical radiation source (410, 510) to externally clock the sampling process of the DAQ device (440). The system may employ over-sampling and various digital signal processing methods to improve image quality. The system further includes multiple stages of routers (1418, 1425) connecting the light source (1410) with a plurality of interferometers (1420a-1420n) and a DAQ system (1450) externally clocked by frequency clock signals to perform high-speed multi-channel optical imaging of samples.

Disclosed herein are optical integration technologies, designs, systems and methods directed toward Optical Coherence Tomography (OCT) and other interferometric optical sensor, ranging, and imaging systems wherein such systems, methods and structures employ tunable optical sources, coherent detection and other structures on a single or multichip monolithic integration. In contrast to contemporary, prior-art OCT systems and structures that employ simple, miniature optical bench technology using small optical components positioned on a substrate, systems and methods according to the present disclosure employ one or more photonic integrated circuits (PICs), use swept-source techniques, and employ a widely tunable optical source(s). In another embodiment the system uses an optical photonic phased array. The phase array can be a static phased array to eliminate or augment the lens that couples light to and from a sample of interest or can be static and use a spectrally dispersive antenna and a tunable source to perform angular sweeping. The phased array can be active in 1 or 2 dimensions so as to scan the light beam in angle. The phased array can also adjust focus. The phased array can implement an optical waveform that will extend depth of field focus for imaging. The phase array can also be a separate standalone element that is fed by one or more optical fibers. The phased array can be for scanning a biomedical specimen used in conjunction with a swept-source OCT system, can be used in a free-space coherent optical communication system for beam pointing or tracking, used in LIDAR applications, or many other beam control or beam steering applications.

An optical coherence tomographic device may include a light source, a measurement light generator, a reference light generator, an interference light generator, an interference light detector, and a processor. The interference light detector may include a first and second detector that convert interference light to interference signals, a first signal processing unit that samples the interference signal from the first detector, and a second signal processing unit that samples the interference signal from the second detector. Each of the first and second signal processing units may sample the interference signal at a timing from outside. Light generated by the measurement light generator may at least include first and second correction light. The processor may correct a time lag between sampling timings of the first and second signal processing units by using a first and second correction signal converted from the first and second correction light.

An optical coherence tomography (OCT) system electrically mixes a signature signal with an OCT signal (e.g., an interferogram) output by a photodetector of the OCT system. The signature signal may be a signal output by a photodetector that detects an optical signal from a fiber Bragg grating. The signature signal may then be time delayed before combination with the OCT signal. A series of interferograms are then aligned according to the signature signal. A rescaling signal may be similarly electrically mixed with the signature and OCT signals.

The present application in some embodiments relates to methods for reducing noise and/or clutter when measuring a spectrum, particularly but not only for OCT imaging. In some embodiments a light source is synchronized with a detector. For example a narrow band light source is synchronized with a narrow band detector. For example, the light source may scan over multiple frequency bands and/or the detector may be tuned to a frequency band synergetic to the band of the light source. For example the light source and detector may be tuned to overlapping narrow bands. Optionally the detector has a sensor set for each frequency band. Optionally some sensor sets are individually resettable. For example each set may have a reset circuit. For example, a sensor set for a band not currently being measured is deactivated.