The present subject matter at least provides an apparatus for characterization of a slab of a material. The apparatus comprises two or more frequency-domain optical-coherence tomography (FD-OCT) probes configured for irradiating the slab of material, and detecting radiation reflected from the slab of material or transmitted there-through. Further, a centralized actuation-mechanism is connected to the OCT probes for simultaneously actuating elements in each of the OCT probes to cause a synchronized detection of the radiation from the slab of material. A spectral-analysis module is provided for analyzing at least an interference pattern with respect to each of the OCT probes to thereby determine at least one of thickness and topography of the slab of the material. Further, in some embodiments, the slab of material may include a passivation layer. The apparatus may be configured to determine a thickness of the passivation layer.

A method for measuring the thickness of a specimen, according to an embodiment, can measure the thickness of a specimen having multiple layers in a contactless and non-destructive manner. In addition, when the refractive indexes of materials forming the respective layers are already known, the thicknesses of the respective layers can be integrally measured through differences in reflection times of terahertz waves with respect to the respective layers of the specimen, thereby measuring the thickness of the specimen, such that the time taken for measuring the thickness of the specimen can be reduced. Furthermore, when the refractive indexes of the materials forming the respective layers are not known, the refractive indexes of the respective layers can be measured through differences in transmission times and reflection times of terahertz waves with respect to the respective layers of the specimen, and at the same time, the thicknesses of the respective layers can be measured through differences in transmission times or reflection times of terahertz waves with respect to the respective layers of the specimen, so that the thickness of various specimens can be measured. As such, the present invention has a wide range of applications.

The optical displacement meter generates, from each position of a plurality of pixel rows in a U direction and a peak position in a V direction, a plurality of profiles of the X-Z cross section, and measures a three-dimensional shape of the measuring object based on the plurality of profiles acquired at different positions in the Y direction. The optical displacement meter determines, based on whether a profile exists in a blind spot region in which it is impossible to measure a height which occurs in a Y-Z cross section corresponding to an angle formed between a light projecting axis of a light projecting section and a light receiving axis of an image sensor based on a principle of triangulation, a part of the three-dimensional shape generated by a measuring unit as an erroneous detection value.

A production system for measuring product thickness in tortilla and tortilla chip production includes a production line, including a cooker/grinder, a sheeter/cutter, and a conveyor belt; and a displacement measurement unit, including a processor, non-transitory memory, an input/output component, a laser sensor for measuring vertical displacement of the conveyor belt and objects thereon, a laser controller, and a displacement calculator. Also disclosed is a method for thickness measurement, including capturing samples, calculating a vertical displacement probability density function, and calculating average product thickness.

There is provided a method for manufacturing a semiconductor structure, including: preparing a plate-like semiconductor structure; and inspecting the semiconductor structure, the inspection of the semiconductor further including: performing a measurement of irradiating a surface of the semiconductor structure with a light from a light source in an oblique direction to the surface, and detecting a reflected light reflected or scattered by the surface by a two-dimensional detector, at a plurality of locations within at least a predetermined range of the surface of the semiconductor structure, to acquire a reflected light distribution that is a distribution of an integrated value obtained by integrating intensity of the reflected light measured at the plurality of locations, with respect to a position at the detector; and fitting the reflected light distribution by a multiple Gaussian function obtained by adding at least a first Gaussian function and a second Gaussian function distributed more widely than the first Gaussian function, to acquire a parameter of the second Gaussian function as an index corresponding to a surface roughness of the semiconductor structure.

The thickness of accumulated fiber can be appropriately measured when accumulating and processing fiber. A measuring device includes a distributor 60 that disperses material containing fiber; a mesh belt 72 that accumulates material dispersed by the distributor 60; a roller unit 650 that compresses a second web W2 accumulated on the mesh belt 72; and a measurement device 400 that measures the thickness of the second web W2 after compression by the roller unit 650.

According to an embodiment of the invention, a sensor includes a first element part. The first element part includes a first member and a first element. The first member is tubular and extends along a first direction. The first member includes a first opening and a second opening. A direction from the second opening toward the first opening is along the first direction. The first element includes a vibratile first membrane, and a first supporter supporting the first membrane. The second opening is between the first opening and the first membrane in the first direction.

Time-of-flight measurements calculate the absolute caliper of a moving film independent of the film's index of refraction. A reflective fiber coupled terahertz gauge is mounted co-axially with a temperature stabilized Z-sensor positioned within a scanner head. The terahertz gauge monitors four reflections: (1) the reflection from a sensor window, (2, 3) the reflections from the top and bottom surfaces of the sheet product being measured, and (4) the reflection from a reflector that is placed behind the sheet. The Z-sensor monitors the distance between the reflector and the sensor window. The terahertz reflection delays together with the Z distance measurements allow extraction of the caliper. Since the time delay due to the sheet is a function of thickness and index of refraction, the basis weight of the sheet can be determined by using a calibration of the sensor relating basis weight of the product to time delay.

A production system for measuring product thickness in tortilla and tortilla chip production includes a production line, including a cooker/grinder, a sheeter/cutter, and a conveyor belt; and a displacement measurement unit, including a processor, non-transitory memory, an input/output component, a laser sensor for measuring vertical displacement of the conveyor belt and objects thereon, a laser controller, and a displacement calculator. Also disclosed is a method for thickness measurement, including capturing samples, calculating a vertical displacement probability density function, and calculating average product thickness.

A tunable acoustic gradient (TAG) lens includes an acoustic wave generating element and a refractive fluid in a casing cavity surrounded by a lens casing. The lens casing includes case ends which each include a window configuration, a case end rim portion and an enhanced axial compliance portion. The window configuration includes a window and a window mounting portion having an overall window mount dimension along the axial direction. The enhanced axial compliance portion is coupled between the window mounting portion and the case end rim portion and includes a reduced thickness region characterized by a material thickness that is at most 75% of the associated window mount dimension. The axial compliance portion is configured to enhance the axial deflection of the window mounting portion compared to the case end rim portion, when a periodic drive signal is applied to the acoustic wave generating element.