A method of determining outdoor characteristics of a photochromic optical article includes: determining environmental conditions for an area; positioning the optical article to face a first direction; determining a first incident irradiance on the optical article; determining a first surface temperature and first spectrum of the optical article; rotating the optical article to face a second direction; determining a second surface temperature and Full Characterization of Lens second spectrum of the optical article; determining a second incident irradiance on the optical article; and generating a prediction model of spectral transmission of the optical article. Further using environmental and climate conditions and to select a photochromic article most appropriate for an area.

An object of the present invention is to provide an immersion detection system and an immersion detection method capable of eliminating module replacement in the occurrence of immersion and simplifying system management. An immersion detection system according to the present invention includes: an immersion detection sensor having two optical fibers connected in series such that end faces of the two optical fibers abut on each other with a predetermined gap; an optical measurer that causes test light with a plurality of wavelengths to enter an optical transmission line having a plurality of the immersion detection sensors connected in series with optical fibers and measures a return loss of the test light at the immersion detection sensor for each of the wavelengths and for each of the immersion detection sensors; and a determiner that averages, for each of the immersion detection sensors, the return losses for the wavelengths and performs threshold determination on the presence or absence of immersion.

According to one aspect of the presently disclosed subject there is provided a device configured figured to allow illumination of light towards a tunable filter, each time towards a different portion thereof, and detect the optical response, (e.g., transmission or reflection from the portion that is illuminated with light). By detecting optical response of isolated illuminations towards different portions of the tunable filter each time, the state of the tunable filter at the illuminated portion, e.g. the optical gap between a movable member and a stationary member of the tunable filter, can be determined. By monitoring different portions of the tunable filter, the general state of the tunable filter is determined. For example, the general state of the tunable filter may be determined based on the optical gaps at different portions of the tunable filter while the actuation parameters are maintained unchanged.

A method for determining an index-of-refraction profile of an optical object, which has a cylindrical surface and a cylinder longitudinal axis, said method comprising the following method steps: (a) scanning the cylindrical surface of the object at a plurality of scanning locations by means of optical beams; (b) capturing, by means of an optical detector, a location-dependent intensity distribution of the optical beams deflected in the optical object; (c) determining the angles of deflection of the zero-order beams for each scanning location from the captured intensity distribution, comprising eliminating beam intensities, and (d) calculating the index-of-refraction profile of the object on the basis of the angle-of-deflection distribution, wherein method steps (a) and (b) are carried out with light beams having at least two different wavelengths.

In a direct stimulus value reading type colorimetric photometer, first, second, and third colorimetric optical systems have spectral responsivities approximate to first, second, and third parts of the color matching function, respectively. A deriving unit derives a colorimetric value corresponding to a case in which the color matching function is selected as an evaluation function for colorimetry and a photometric value corresponding to a case in which the spectral luminous efficiency is selected as an evaluation function for photometry (i.e. “CASE”) from three signals. The spectral luminous efficiency is not consistent with any one of the first, second, and third parts. A fourth colorimetric optical system may have spectral responsivity approximate to the spectral luminous efficiency, and the deriving unit may derive the colorimetric value corresponding to the CASE from a fourth signal.

An additive manufacturing machine includes a laser light source, a beam entry window, a recoater, a plurality of light sources attached to the recoater, a photosensor, and a controller. The laser light source emits laser light to selectively melt one or more portions of a working layer of a powder bed during additive manufacturing of a part. The beam entry window is positioned between the powder bed and the laser light source. The recoater moves across the powder bed to spread the working layer. The photo sensor senses intensity of light emitted by each of the plurality of light sources through the beam entry window. The controller correlates sensed intensity of the light emitted by each of the plurality of light sources through the beam entry window to corresponding positions on the beam entry window based on locations of each of the plurality of light sources.

A method implemented by computer means for determining at least one optical parameter of a lens of eyewear adapted for a person, the method comprising: —an image reception step, during which at least a first image and a second image are received, the first image comprising a front view of the face of the person with at least one part of an eye of the person being directly visible, and the second image comprising a front view of the face of the person with said part of the eye of the person being visible through at least part of the lens, and —an optical parameter determination step, during which at least one optical parameter of the lens is determined based on a comparison between said part on the first and the second image.

A refractive index measurement method uses an interference optical system which divides light from a light source having a plurality of discrete wavelengths into test light and reference light, causes the test light transmitted through the target to interfere with the reference light, and detect the interference light. The refractive index measurement method determines a first optical delay amount of the interference optical system so that a first and a second wavelength become adjacent to a wavelength corresponding to an extremal value of a phase of the interference light, measures phases of interference light at the first and second wavelengths at the first optical delay amount, and calculates a phase difference between a plurality of the discrete wavelengths at a predetermined optical delay amount using the first optical delay amount, the phases of the interference light at the first and second wavelengths to calculate the refractive index of the target.

An optical encoder of the present invention includes a light-receiving element unit 5, moving slit 2 and fixed slit 3. The light-receiving element unit 5 includes a pattern 5B for detecting infiltration of liquid.

A system is disclosed for measuring the transmission of light through a pair of eyeglasses having least one eyeglass lens mounted in a spectacle frame having a position of wear. The system comprises a light source, a support for mounting the eyeglasses, and a light detector coupled to the support. The support is configured to mount the eyeglasses with the position of wear relative to the light detector. A microprocessor is coupled to the light detector, and a display coupled to the processor. The processor receives spectral data from the light detector and outputs the spectral data to the display as a spectral curve.