摘要:
A method and device realize shallow gratings-based planar beam splitter/combiner. Non-trivial phase shifts between different ports of resulting interferometers are used to acquire full-field phase measurements. The non-trivial phase shifts between different ports of the planar beam splitter/combiner can be adjusted by simply shearing one grating with respect to the second grating. The two shallow diffraction gratings are harmonically-related and can be recorded on a single substrate for compact interferometric based schemes. During the recording process, the two gratings are aligned such that the grating planes and the grating vectors are parallel to that of each other. The relative phase of the recording beams controls the shearing between the recorded harmonically-related shallow phase gratings. The relative shearing of the two gratings defines the non-trivial phase shift between different ports of the compact planar beam splitter/combiner.
摘要:
Optical coherence tomography (OCT) may be used to acquire cross-sectional or volumetric images of any specimen, including biological specimens such as the retina. Additional processing of the OCT data may be performed to generate images of features of interest. In some embodiments, these features may be in motion relative to their surroundings, e.g., blood in the retinal vasculature. In some embodiments, an acquired image may be degraded by motion artifact. The proposed invention describes OCT system embodiments that may be configured for multi-scale imaging, with the capability of switching between low or high lateral resolution, and with the assistance of adaptive optics for aberration correction. The invention also describes a method for enhancing OCT image quality by reducing or eliminating the negative effects introduced by sources and speed by performing bidirectional scanning. The proposed invention describes a method for the combination of images acquired by OCT for the automatic registration and averaging of features, such as blood vessels in images acquired with OCT angiography.
摘要:
En face views of OCT volumes provide important and complementing visualizations of the retina and optic nerve head investigating biomarkers of diseases affecting the retina. We demonstrate the combination of real time processing of OCT volumetric data for axial tracking. In combination with a Controllable Optical Element (COE), this invention demonstrates acquisition, real time tracking, automated focus on depth resolved en face layers extracted from a volume, and focus stacked OCT volumes with high resolution throughout an extended depth range.
摘要:
A thermal inorganic resist for lithographic processes and image creation is disclosed. In one embodiment an In layer of 15 nm is deposited, followed by a Bi layer of 15 nm. Upon exposure to a optical light pulse of sufficient intensity the optical absorption heats the film above the eutectic melting point (110° C. for BiIn) and the resist forms an alloy in the exposed area, replicating patterns projected on its surface. Optical characteristics of the alloyed layers are in these resists typically different from the unexposed layers creating a visual image of the exposure pattern before the development etch aiding in exposure control. The resist layer is then stripped, leaving the pattern layer on the substrate. In resists showing significant optical differences (such as BiIn) after exposure this same material can be used to create images for data storage, and, when transparent, photomasks for optical lithography.
摘要:
Optical coherence tomography (OCT) may be used to acquire cross-sectional or volumetric images of any specimen, including biological specimens such as the retina. Additional processing of the OCT data may be performed to generate images of features of interest. In some embodiments, these features may be in motion relative to their surroundings, e.g., blood in the retinal vasculature. The proposed invention describes a combination of images acquired by OCT, manual segmentations of these images by experts, and an artificial neural network for the automated segmentation and classification of features in the OCT images. As a specific example, the performance of the systems and methods described herein are presented for the automatic segmentation of blood vessels in images acquired with OCT angiography.
摘要:
En face views of OCT volumes provide important and complementing visualizations of the retina and optic nerve head investigating biomarkers of diseases affecting the retina. We demonstrate the combination of real time processing of OCT volumetric data for axial tracking. In combination with a Controllable Optical Element (COE), this invention demonstrates acquisition, real time tracking, automated focus on depth resolved en face layers extracted from a volume, and focus stacked OCT volumes with high resolution throughout an extended depth range.