Abstract:
A frequency-conversion crystal annealing process includes a first ramp-up period (e.g., increasing the crystal's temperature to a first set point in the range of 100° C. to 150° C. over about 2 hours), a first fixed temperature period (e.g., maintaining at the first set point for 10 to 20 hours), a second ramp-up period (e.g., increasing from the first set point to a second set point above 150° C. over about 1 hour or more), a second fixed period (e.g., maintaining at the second set point for 48 to 300 hours), and then a temperature ramp-down period (e.g., decreasing from the second set point to room temperature over about 3 hours). Transitions from the first and second fixed temperature periods are optionally determined by —OH bonds absorption levels that are measured using Fourier transform infrared spectroscopy, e.g., by monitoring the absorption of —OH bonds (including H2O) near 3580 cm−1 in the infra-red spectrum.
Abstract:
A sensor head is described herein. The sensor head can include a first piece, where the first piece can include a body having an outer surface and an inner surface. The first piece can also include a light source cavity disposed in the body at the inner surface. The first piece can further include an optical device cavity disposed in the body at the inner surface. The first piece can also include an ellipsoidal cavity disposed in the body at the inner surface, where the ellipsoidal cavity is disposed adjacent to the optical device cavity. The first piece can further include a receiving device cavity disposed in the body adjacent to the inner surface that forms the ellipsoidal cavity. The first piece can also include at least one channel disposed in the body.
Abstract:
A frequency-conversion crystal annealing process includes a first ramp-up period (e.g., increasing the crystal's temperature to a first set point in the range of 100° C. to 150° C. over about 2 hours), a first fixed temperature period (e.g., maintaining at the first set point for 10 to 20 hours), a second ramp-up period (e.g., increasing from the first set point to a second set point above 150° C. over about 1 hour or more), a second fixed period (e.g., maintaining at the second set point for 48 to 300 hours), and then a temperature ramp-down period (e.g., decreasing from the second set point to room temperature over about 3 hours). Transitions from the first and second fixed temperature periods are optionally determined by —OH bonds absorption levels that are measured using Fourier transform infrared spectroscopy, e.g., by monitoring the absorption of —OH bonds (including H2O) near 3580 cm−1 in the infra-red spectrum.
Abstract:
An optical system for detecting contaminants and defects on a test surface includes an improved laser system for generating a laser beam and optics directing the laser beam along a path onto the test surface, and producing an illuminated spot thereon. A detector and ellipsoidal mirrored surface are also provided with an axis of symmetry about a line perpendicular to the test surface. In one embodiment, an optical system for detecting anomalies of a sample includes the improved laser system for generating first and second beams, first optics for directing the first beam of radiation onto a first spot on the sample, second optics for directing the second beam onto a second spot on the sample, with the first and second paths at different angles of incidence to the sample surface. In another embodiment, a surface inspection apparatus includes an illumination system configured to focus beams at non-normal incidence angles.
Abstract:
A mode-locked laser system operable at low temperature can include an annealed, frequency-conversion crystal and a housing to maintain an annealed condition of the crystal during standard operation at the low temperature. In one embodiment, the crystal can have an increased length. First beam shaping optics can be configured to focus a beam from a light source to an elliptical cross section at a beam waist located in or proximate to the crystal. A harmonic separation block can divide an output from the crystal into beams of different frequencies separated in space. In one embodiment, the mode-locked laser system can further include second beam shaping optics configured to convert an elliptical cross section of the desired frequency beam into a beam with a desired aspect ratio, such as a circular cross section.
Abstract:
The present invention provides a method and system to correct for angular spread within an HDR used to determine IR optical constants. An algorithm simulates the transmission and polarized reflection actually observed. This is achieved by averaging power scattering over an angular spread corresponding to the size of the HDR mirror. Such an algorithm may incorporate corrections for angular spread that may be used to determine the thickness of a film (coating) as well as the optical constants of the film or coating on low loss ranges.
Abstract:
A detecting system using a spectrum measurement device and detecting an object is provided. The system includes: a sampling module and spectrum measurement devices assembled to the sampling module. The sampling module provides an illumination beam to the object and collects measurement beams reflected by the object to the spectrum measurement devices. The illumination beam has an illumination light waveband. The measurement beams have the illumination light waveband. The spectrum measurement devices include first and second spectrum measurement devices. The first spectrum measurement device includes a digital micromirror device. The measurement beams include first and second measurement beams transmitted to the first and second spectrum measurement devices respectively. The first spectrum measurement device detects a portion of the illumination light waveband of the first measurement beam, and at the same time the second spectrum measurement device detects another portion of the illumination light waveband of the second measurement beam.
Abstract:
A small-sized gas detection apparatus with high measurement accuracy is provided. The gas detection apparatus includes a light emitting portion (1); a light receiving portion (2); a first mirror (3) that has a quadric reflective surface and reflects light emitted from the light emitting portion; and a second mirror (4) that has a quadric reflective surface and reflects the light reflected by the first mirror to the first mirror. The quadric surfaces of the first mirror and the second mirror have convex portions facing in a same direction. The first mirror reflects the light reflected by the second mirror to the light receiving portion. When one surface of a substrate on which the light emitting portion and the light receiving portion are mounted is used as a reference plane, the first mirror and the second mirror are provided at positions higher than the reference plane and have different heights.
Abstract:
A system and method for monitoring and operating one or more light emitting devices is disclosed. In one example, light intensity within a dual elliptical reflecting chamber is sensed and operation of a fiber curing system is adjusted in response to an amount of sensed light energy.
Abstract:
An optical element includes a main body formed of a light transmissive material and including an arc-shaped optical path, and a gap formed on the arc-shaped optical path in the main body. The gap may have a notch shape. The main body may have a semicircular plate shape. The main body may have a hemispherical shape.