A dielectric layer comprising an embossed surface and a flat surface which is located at a side opposite to the embossed surface is provided. The plane that approximates the flat surface is the X-Y plane, and the normal direction to the X-Y plane is the Z direction. The embossed surface has inclined surfaces that are inclined with respect to the Z direction, and the inclined surfaces reflect incident light incident on the dielectric layer and emerge reflected light. The elevation angle, which is an angle between the inclined surface and the X-Y plane, is α. The refractive index of the dielectric layer is n. These values satisfy Formula (1): sin α≤(1/n)<sin 2α.

Methods of producing luminescence by application of a time-varying electrical signal to an electroluminescent device are disclosed whereby the entire system remains at open circuit. At least one article, substance or material, the “object”, is employed to alter the electrical signal to the area of the electroluminescent device to a level sufficient to change light emission. Methods are disclosed to relate the light intensity thus produced to a property of the object thereby allowing a measurement of the property. The method may optionally use one or more additional circuit components.

An optical coherence tomography (OCT) measurement system for precision measurement of a translucent sample is provided. The system includes an optical coherence tomography (OCT) imaging system comprising a broadband light source, a reference path with reference path length, and sample path with a beam scanning assembly and an imaging lens assembly; a sample positioning assembly including an immersion bath for positioning the translucent sample within an immersion bath; a position assembly for locating the translucent sample within a field of view (FOV) of the OCT imaging system; an immersion lens assembly associated with the imaging lens assembly configured to eliminate an air to bath refractive interface between a distal surface of the OCT imaging lens including an immersion tip and a surface of the bath; a first set of calibration parameters that relate a position of a scanning beam at an imaging plane to drive signals of the scanning assembly; and a second set of calibration parameters for relating an optical path length or optical path length variation of the scanning beam at an imaging plane to the position of the scanning beam or to the drive signals of the scanning assembly.

A test pattern (170) comprising a set of dots (174) which define a first ellipse (176) of best fit in which the major and minor axes R1, R2 are equal (i.e. a circle) is displayed on a plane surface and a digital image of the (usually distorted) test pattern seen through a lens is captured. A second ellipse of best fit joining the dots in the set is derived from the distorted test pattern in the image. Characteristics of the first and second ellipses are compared to determine the degree and nature of distortion to the test pattern, from which the power of the lens is calculated. The major and minor axes of the first and second ellipses may be compared. The test pattern can include a number of said sets of dots distributed over an area of the surface with each set being analysed to determine the optical parameters of the lens at multiple locations.

A robotic system automatically aligns, and/or tests alignment of, a lens to a digital camera or other workpiece. The system includes an optical target, an intermediate lens and a plurality of collimators peripheral to the intermediate lens to accommodate a wide range of fields of view of the workpieces, without requiring changes in equipment hardware. When manufacturing or testing a workpiece with a relatively narrow field of view, the entire field of view of the workpiece can be filled with a view of the target through the intermediate lens, and the collimators need not be used. However, when manufacturing or testing a camera having a relatively large field of view, the intermediate lens is used to fill a central portion of the field of view with an image of the target, and the collimators are used to fill a remaining portion of the field of view with images of reticles.

A parameter measurement device of a light deflector includes a photodetector that receives output light from the light deflector, a biaxial translation automatic stage that moves the photodetector to a plurality of positions, and a signal processing device that calculates the wavelength of the output light of a wavelength sweeping light source for each time, calculates the wavelength of the light received from the light deflector by the photodetector based on the output signal of the photodetector and a previously-calculated wavelength, and calculates the incident angle of the output light beam of the wavelength sweeping light source onto the diffraction grating and an angle formed by an L-axis and a line perpendicular to the surface of the diffraction grating by performing fitting so that the coordinates of the photodetector that are obtained for each position of the photodetector and the wavelength of the light conform to a prescribed relational expression.

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.

The present invention is to provide a backscattered light amplification device, an optical pulse test apparatus, a backscattered light amplification method, and an optical pulse test method for amplifying a desired propagation mode of Rayleigh backscattered light with a desired gain by stimulated Brillouin scattering in a fiber under test having the plurality of propagation modes. The backscattered light amplification device according to the present invention is configured to control individually power, incident timing, and pulse width of a pump pulse for each propagation mode when the pump pulse is incident in a plurality of propagation modes after the probe pulse is input to the fiber under test in any propagation mode.

An inspecting unit for use in a laser processing apparatus includes a camera configured to image a spot of a laser beam, and a processing unit configured to generate a light intensity at two-dimensional X-Y coordinates corresponding to a two-dimensional image imaged by the camera. The processing unit includes a determining unit configured to generate a three-dimensional approximate curve or an approximate curved surface such that the light intensity corresponding to the two-dimensional coordinates is set as a Z-coordinate, and determine that there is dirt, a flaw, or an abnormality in an optical system on an optical path on the laser oscillator side of a position at which the spot is imaged when a difference between the first light intensity of the Z-coordinate corresponding to the two-dimensional coordinates and a second light intensity indicated by the approximate curve or the approximate curved surface exceeds an allowable value.

A metrology system is disclosed, in accordance with one or more embodiments of the present disclosure. The metrology system includes a stage configured to secure a sample, one or more diffraction-based overlay (DBO) metrology targets disposed on the sample. The metrology system includes a light source and one or more sensors. The metrology system includes a set of optics configured to direct illumination light from the light source to the one or more DBO metrology targets of the sample, the set of optics including a half-wave plate, the half-wave plate selectively insertable into an optical path such that the half-wave plate selectively passes both illumination light from an illumination channel and collection light from a collection channel, the half-wave plate being configured to selectively align an orientation of linearly polarized illumination light from the light source to an orientation of a grating of the one or more DBO metrology targets.