A method and apparatus to maintain image focus on parts such as wafers, circuit boards, or high-density substrates as the part is being inspected. Focus performance is independent of feature and trace orientation and density. This apparatus can be easily integrated into an inspection system and can maintain focus on parts with high aspect ratio structures and or low or non-reflective insulators. It enables the inspection of high-density fine line products requiring the use of high resolution, high numerical aperture (NA) imaging optics with small depths of focus (DOF) that must be kept in focus during the inspection.

Stack fault inspection apparatus and method are disclosed. The apparatus includes a sample stage fixing the silicon carbide substrate and allow the incident light to scan the substrate surface; an incident light source configured to irradiate a vertical illumination light of a wavelength corresponding to an energy greater than a band gap energy of the substrate to at least a portion of a surface of the substrate in a direction substantially perpendicular to the surface of the substrate; a photomultiplier tube (PMT) configured to obtain a photoluminescence mapping image having a wavelength corresponding to the band gap energy of the substrate from the surface of the substrate; and a controller configured to process the mapping image and identify stacking faults.

A method of detecting a condition in a subject comprises the steps of contacting cells of the subject with single-walled carbon nanotubes (SWCNTs), monitoring photoluminescence emitted by SWCNTs internalized into the cells and generating an SW-CNT emission profile, comparing the SWCNT emission profile to a control emission profile for the SWCNTs to produce a result, and determining a likelihood of having the condition in the subject based on the result from the comparing step. Also disclosed is a method for screening agents capable of changing endocytic environment using SWCNTs.

An inspection apparatus is provided that comprises an optical target including a solid host material and a fluorescing material embedded in the solid host material. The solid host material has a predetermined phonon energy HOST.sub.PE. The fluorescing material exhibits a select ground energy level and a target excitation (TE) energy level separated from the ground energy level by a first energy gap corresponding to a fluorescence emission wavelength of interest. The fluorescing material has a next lower lying (NLL) energy level relative to the TE energy level. The NLL energy level is spaced a second energy gap FM.sub.EG2 below the TE energy level, wherein a ratio of the FM.sub.EG2/HOST.sub.PE is three or more.

A process for determining the type of a diamond, wherein the type of diamond is determined by the steps of (i) measuring the fluorescence lifetime characteristics of colour centres of a diamond of unknown type (110a); and (ii) determining the type of diamond by comparing the fluorescence lifetime characteristics measured at step (i) with the fluorescence lifetime characteristics of colour centres of known diamond types (120a), wherein the fluorescence lifetime characteristics of colour centres are indicative of the physical properties of a diamond, which are indicative of the type of a diamond.

A detecting apparatus for use in specifying regions having different impurity concentrations in an ingot includes an ingot holding unit having a holding surface for holding the ingot thereon, an excitation light source for applying excitation light having a predetermined wavelength to a face side of the ingot held on the holding surface, and a photodetector for detecting fluorescence emitted from the ingot upon exposure to the excitation light and generating an electric signal representing a number of photons of only light whose wavelength is in an infrared radiation range, of the detected fluorescence.

A SiC epitaxial wafer including a high-concentration epitaxial layer having an impurity concentration of 1×10.sup.18 cm.sup.−3 or more, and the number or positions of basal plane dislocations included in the high-concentration epitaxial layer have been identified

A biological substance detection method for detecting a biological substance specifically in a pathological specimen, includes a step of immunologically staining the pathological specimen using a fluorescent label, a step of staining the pathological specimen with a staining reagent for morphology observation purposes (eosin) to observe the morphology of the pathological specimen, a step of irradiating the stained pathological specimen with excited light to cause the emission of a fluorescent and detecting the biological substance in the pathological specimen. In the step of immunologically staining the pathological specimen, a special fluorescent particle for which the excitation wavelength appears in a region that is different from the excitation wavelength region of eosin is used as the fluorescent label.

A method of detecting a Facet region includes: a fluorescence luminance detecting step of detecting fluorescence luminance unique to SiC by irradiating a SiC ingot with exciting light having a predetermined wavelength from a top surface of the SiC ingot; and a coordinate setting step of setting a region in which the fluorescence luminance is equal to or higher than a predetermined value in the fluorescence luminance detecting step as a non-Facet region, setting a region in which the fluorescence luminance is lower than the predetermined value in the fluorescence luminance detecting step as a Facet region, and setting coordinates of a boundary between the Facet region and the non-Facet region.

The disclosure is directed to systems, compositions and methods for tagging, identifying and authenticating bulk liquids. Specifically, the disclosure relates to methods, compositions and systems for selectively and specifically identifying bulk liquids as authentic using, as a tagging compound, photoluminescent carbon nanostructures (PCN's) suspended in a continuous phase that is thermodynamically incompatible with non-polar bulk liquid and/or substantially low concentration of PCNs; and incorporating the suspension into the liquid, wherein the suspension is incorporated at a concentration of continuous phase that is at least one of being below the solubility limit of the suspension's continuous phase in the bulk liquid and a concentration that cannot be observed unaided to the naked eye.