Abstract: Systems and methods for improved acquisition of ophthalmic optical coherence tomography data are presented, allowing for enhanced ease of use and higher quality data and analysis functionality. Embodiments include automated triggering for detecting and initiating collection of OCT ophthalmic data, an automated technique for determining the optimal number of B-scans to be collected to create the highest quality image and optimize speckle reduction, automated review of fundus images collected with an adjunct imaging modality to guide the OCT data collection, a single scan protocol in which a large field of view is collected with HD B-scans embedded at different locations depending on automated analysis of either a fundus image or sparse OCT scan, and various scan configurations for imaging eyes with large axial depth range.

Abstract: Systems and methods for sub-aperture correlation based wavefront measurement in a thick sample and correction as a post processing technique for interferometric imaging to achieve near diffraction limited resolution are described. Theory, simulation and experimental results are presented for the case of full field interference microscopy. The inventive technique can be applied to any coherent interferometric imaging technique and does not require knowledge of any system parameters. In one embodiment of the present application, a fast and simple way to correct for defocus aberration is described. A variety of applications for the method are presented.

Abstract: Systems and methods for applying the concept of lightfield sensors to fundus photography are presented. In one embodiment, the ability to isolate specific regions of the collected lightfield are used to reduce the effects of glare in a fundus image. Additional embodiments in which aberrations can be characterized and removed, an image from a particular plane in the collected light field is used to aid in instrument alignment, and dynamic optimization of collection pupil diameter is accomplished are also presented.

Abstract: Swept source designs that eliminate or significantly reduce artifacts in optical coherence tomography are presented. One embodiment of the present invention is a source design that frequency shifts the coherence revival interference signal to a frequency larger than the A/D detection bandwidth or the post-processing bandwidth. In another embodiment, the introduced frequency shift is large enough to introduce a Doppler shift of the modes of the laser, which causes a blurring of the comb function, and thus eliminates or reduces mode hopping. In another embodiment, adjusting the cavity optical path length prior to data acquisition depending on the given optical layout configuration to reduce or eliminate coherence revival artifacts is described.

Abstract: Systems and methods for reducing noise in balanced detection based optical coherence tomography (OCT) systems are described. Embodiments including both optical hardware and electronic based solutions to spectrally filter and attenuate the source reference light in optical coherence tomography in an effort to reduce RIN and FPN noise in OCT systems are presented. A novel application to electronic balanced detection schemes in which a single source of reference detection is balanced against the interferometric signals from multiple interferometers is also presented.

Abstract: Systems and methods for increasing the duty cycle and/or producing interleaved pulses of alternating polarization states in swept-source optical coherence tomography (OCT) systems are considered. Embodiments including improved buffering, frequency selecting filter sharing among multiple SOAs, intracavity switching, and multiple wavelength bands are described. The unique polarization properties of the source configurations have advantages in speckle reduction, polarization-sensitive measurements, polarization state dependent phase shifts, spatial shifts, and temporal shifts in OCT measurements.

Abstract: Systems and methods for improvements to optical coherence tomography systems for operating in different imaging modes are presented. In one embodiment, a system for identifying the presence and type of an adjunct lens operably connected to the OCT instrument for changing between imaging modes in the system is described. In a second embodiment, a system for dynamically autofocusing the OCT system depending on the layer of interest is presented. In a third embodiment, the overall power of the system used for imaging can be adjusted depending on the location and type of scan desired while accounting for the safety standards for recommended light exposure.

Abstract: Systems and methods for improved acquisition of ophthalmic optical coherence tomography data are presented, allowing for enhanced ease of use and higher quality data and analysis functionality. Embodiments include automated triggering for detecting and initiating collection of OCT ophthalmic data, an automated technique for determining the optimal number of B-scans to be collected to create the highest quality image and optimize speckle reduction, automated review of fundus images collected with an adjunct imaging modality to guide the OCT data collection, a single scan protocol in which a large field of view is collected with HD B-scans embedded at different locations depending on automated analysis of either a fundus image or sparse OCT scan, and various scan configurations for imaging eyes with large axial depth range.

Abstract: An improved interferometer measurement system is presented. In a preferred embodiment, a chirped fiber Bragg grating is used as a reference surface in a Fizeau interferometer arrangement for optical coherence tomography imaging of the eye. The grating creates a virtual reference surface near the sample and allows for a relatively short reference arm while maintaining close to zero delay interference conditions.

Abstract: Systems and methods for sub-aperture correlation based wavefront measurement in a thick sample and correction as a post processing technique for interferometric imaging to achieve near diffraction limited resolution are described. Theory, simulation and experimental results are presented for the case of full field interference microscopy. The inventive technique can be applied to any coherent interferometric imaging technique and does not require knowledge of any system parameters. In one embodiment of the present invention, a fast and simple way to correct for defocus aberration is described. A variety of applications for the inventive method are presented.

Abstract: Swept source designs that eliminate or significantly reduce artifacts in optical coherence tomography are presented. One embodiment of the present invention is a source design that frequency shifts the coherence revival interference signal to a frequency larger than the A/D detection bandwidth or the post-processing bandwidth. In another embodiment, the introduced frequency shift is large enough to introduce a Doppler shift of the modes of the laser, which causes a blurring of the comb function, and thus eliminates or reduces mode hopping. In another embodiment, adjusting the cavity optical path length prior to data acquisition depending on the given optical layout configuration to reduce or eliminate coherence revival artifacts is described.

Abstract: A novel imaging method, line-field holoscopy is presented. A line of light is projected across an object to be investigated through an imaging system. The light scattered from the investigated object is combined with reference radiation. The combined light is projected onto a detector providing a confocal restriction in one dimension. Astigmatic optics in the return path transform the light asymmetrically such that at the detector, the line focus is imaged to the confocal restriction, while the orthogonal direction is defocused. Embodiments including a swept source with linear detection array, and spectrometer based systems utilizing a 2D detector array are described. The data may be reconstructed to a B-scan by two-dimensional Fourier transform or other reconstruction method with or without combination of more complex algorithms.

Abstract: Systems and methods for increasing the duty cycle and/or producing interleaved pulses of alternating polarization states in swept-source optical coherence tomography (OCT) systems are considered. Embodiments including improved buffering, frequency selecting filter sharing among multiple SOAs, intracavity switching, and multiple wavelength bands are described. The unique polarization properties of the source configurations have advantages in speckle reduction, polarization-sensitive measurements, polarization state dependent phase shifts, spatial shifts, and temporal shifts in OCT measurements.

Abstract: Systems and methods for reducing noise in balanced detection based optical coherence tomography (OCT) systems are described. Embodiments including both optical hardware and electronic based solutions to spectrally filter and attenuate the source reference light in optical coherence tomography in an effort to reduce RIN and FPN noise in OCT systems are presented. A novel application to electronic balanced detection schemes in which a single source of reference detection is balanced against the interferometric signals from multiple interferometers is also presented.

Abstract: Systems and methods for applying the concept of lightfield sensors to fundus photography are presented. In one embodiment, the ability to isolate specific regions of the collected lightfield are used to reduce the effects of glare in a fundus image. Additional embodiments in which aberrations can be characterized and removed, an image from a particular plane in the collected light field is used to aid in instrument alignment, and dynamic optimization of collection pupil diameter is accomplished are also presented.

Abstract: An improved interferometer measurement system is presented. In a preferred embodiment, a chirped fiber Bragg grating is used as a reference surface in a Fizeau interferometer arrangement for optical coherence tomography imaging of the eye. The grating creates a virtual reference surface near the sample and allows for a relatively short reference arm while maintaining close to zero delay interference conditions.

Abstract: Optical coherence tomograph (OCT) probe device (1) comprising an endoscope (6) which is adapted to be coupled to a light source (2) and has a distal tip portion (6.2), the tip portion (6.2) including focussing lens means (11) and a window (5) for directing light to a subject (7) to be scanned, and for receiving light scattered at the subject (7), to send the scattered light back through the endoscope (6) so that it may be applied to a detector (3) together with reference light, said OCT probe device (1) comprising a beam splitter (13; 17) to separate said reference light from the remaining light, as well as a reference light reflector (4; 20) for reflecting the reference light back so that it is composed to the light returned from the subject (7); the beam splitter (13; 17) and the reference light reflector (4; 20) are located in the tip portion (6.2) of the endoscope means (6) behind the focussing lens means (11) through which the composed light is sent back.