Examples are disclosed that relate to calibration of a stereoscopic display system of an HMD via an optical calibration system comprising a waveguide combiner. One example provides an HMD device comprising a first image projector and a second image projector configured to project a stereoscopic image pair, and an optical calibration system. The optical calibration system comprises a first optical path indicative of an alignment of the first image projector, a second optical path indicative of an alignment of the second image projector, a waveguide combiner in which the first and second optical paths combine into a shared optical path, and one or more boresight sensors configured to detect calibration image light traveling along one or more of the first optical or the second optical path.

Optical gratings, such as those used in waveguide displays, may have large aspect ratios. For example, a grating characteristic (e.g., period, feature size, etc.) can be much smaller than the grating area. Variations in the grating characteristic over the grating area may appear like a secondary grating having a long grating period superimposed on a primary grating for which the optical grating was designed. Because variations responsible for the secondary grating occur over a long distance relative to the primary grating period, it may be difficult to locate and characterize these variations with testing methods designed for shorter distances. The present disclosure presents systems and methods to detect and characterize the secondary gratings quickly and efficiently.

A medical lighting device according to the present invention includes a light source unit that emits light, an optical fiber that guides and emits the light having emitted from the light source unit and having entered inside the optical fiber, first and second detection units that are provided in the vicinity of an emission end including an emission end for the light of the optical fiber and detect the light in the optical fiber, and a control unit that determines, based on detection values of the light detected by the first and second detection units, normality/abnormality in the detection values of the respective detection units and outputs determined results.

Embodiments of the present invention provide an improved method of determining splice losses of mechanically terminated optical connectors in the field, without the need of terminating both sides of the fiber link. Embodiments of the present invention also provide means for improving the quality of mechanical splices as utilized in pre-polished fiber optic connectors for terminating single-mode and multimode optical fibers in the field.

A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

An optical device is formed on an optical integrated circuit (IC) chip. The optical device includes: an optical circuit, a first grating coupler, a second grating coupler, a first 1×2 coupler, and a second 1×2 coupler. The first 1×2 coupler is equipped with a first optical port provided at a single-port end and a second optical port and a third optical port provided at a two-port end. The second 1×2 coupler is equipped with a fourth optical port provided at a single-port end and a fifth optical port and a sixth optical port provided at a two-port end. The first grating coupler is coupled to the first optical port. The second optical port is coupled to the optical circuit. The third optical port is coupled to the fourth optical port. The fifth optical port is coupled to the second grating coupler.

Multi-core fibers are optical fibers each of which has a circular cross section. In each of the multi-core fibers, a plurality of cores are arranged at a prescribed interval, the peripheries thereof are covered by a cladding, and a resin coating is formed on the outer periphery of the cladding. In a cross section of this optical fiber ribbon, said cross section being orthogonal to the length direction, the multi-core fibers are arranged such that the cores of all of the multi-core fibers are all arranged in the same direction. The multi-core fibers are arranged such that central lines of the respective multi-core fibers, said central lines respectively linking three of the cores, all face the thickness direction of the optical fiber ribbon. Furthermore, in the optical fiber ribbon, the arrangement of the cores is substantially constant along the entire length of the optical fiber ribbon in the length direction.

A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

A system and method for measuring refractive index inhomogeneity between plates of a Lightguide Optical Element (LOE) uses an innovative measuring technique based on a shearing interferometric technique conventionally used to observe interference and test the collimation of light beams. Another feature of the current implementation is an innovative method for analyzing the characteristics of the generated interferogram to characterize discrepancies between adjacent plates in an LOE.

An object is to provide a determination device that determines a state of a terminal end portion of a coated optical fiber at any location of the coated optical fiber. Reflection of test light varies in a reflection amount at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. In other words, if the magnitude of the reflection amount at each wavelength can be known, the situation of the terminal end portion of the coated optical fiber can be estimated. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a light intensity ratio of each reflected light beams reflected at the terminal end. In addition, reflection of test light varies in return loss at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. If Rayleigh backscattered light can also be measured when measuring a reflection amount, the return loss can be known for each wavelength, and the situation of the terminal end portion of the coated optical fiber can be estimated from the result. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a return loss at the terminal end.