The disclosed automatic calibration systems and methods provide a repeatable way to detect internal catheter reflections and to shift the internal catheter reflections to calibrate an image.

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.

A method for determining characteristics of a test cavity, the method includes for each of a plurality of optical frequencies within a bandwidth of a tunable laser, measuring interference signals from the test cavity and a reference cavity having a known characteristic. The method includes determining values for the plurality of optical frequencies from the measured interference signals from the reference cavity and the known characteristic of the reference cavity, and determining the characteristic of the test cavity using the determined values of the plurality of optical frequencies.

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.

Interferometric measurement signals are detected by a single optical interferometric interrogator for a length of a sensing light guide and an interferometric measurement data set corresponding to the interferometric measurement signals is generated. The interferometric measurement data set is transformed into a spectral domain to produce a transformed interferometric measurement data set. The transformed interferometric measurement data set is compared to a baseline interferometric data set to identify a time-varying signal corresponding to a time-varying disturbance. The baseline interferometric data set is representative of the sensing light guide not being subjected to the time-varying disturbance. A compensating signal is determined from the time-varying signal and used to compensate at least a portion of the interferometric measurement data set for the time-varying disturbance as part of producing a measurement of the parameter.

A calibration system for calibrating a tilt angle of the fast steering mirror includes a position sensing device configured to generate a beam of electromagnetic radiation, and a diffractive optical element, positioned between the position sensing device and the fast steering mirror, the diffractive optical element being configured to divide the input beam into a plurality of output beams directed to the fast steering mirror. The position sensing device is configured to determine a tilt angle of the fast steering mirror. A method to calibrate a tilt angle of the fast steering mirror is further disclosed.

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).

An optical interrogation system, e.g., an OFDR-based system, measures local changes of index of refraction of a sensing light guide subjected to a time-varying disturbance. Interferometric measurement signals detected for a length of the sensing light guide are transformed into the spectral domain. A time varying signal is determined from the transformed interferometric measurement data set. A compensating signal is determined from the time varying signal which is used to compensate the interferometric measurement data set for the time-varying disturbance. The compensation technique may be applied along the length of the light guide.

Techniques and apparatus for selectively producing half-depth and full-depth OCT images, based on a swept-source OCT interference signal. An example method comprises selecting from a first sampling rate and a second sampling rate, the second sampling rate being twice the first sampling rate, and sampling the swept-source Optical Coherence Tomography (OCT) interference signal at the selected sampling rate, using a k-clock signal having a frequency range corresponding to the first sampling rate, to produce a sampled OCT interference signal. The method further comprises processing the sampled OCT interference signal to obtain an OCT image, such that the resulting OCT image is a half-depth image in the event the first sampling rate is selected and a full-depth image in the event the second sampling rate is selected.

An agile optical imaging system for optical coherence tomography imaging using a tunable source comprising a wavelength tunable VCL laser is disclosed. The tunable source has long coherence length and is capable of high sweep repetition rate, as well as changing the sweep trajectory, sweep speed, sweep repetition rate, sweep linearity, and emission wavelength range on the fly to support multiple modes of OCT imaging. The imaging system also offers new enhanced dynamic range imaging capability for accommodating bright reflections. Multiscale imaging capability allows measurement over orders of magnitude dimensional scales. The imaging system and methods for generating the waveforms to drive the tunable laser in flexible and agile modes of operation are also described.