A method and a device for detecting a focal position of a laser beam, particularly a machining laser beam in a laser machining head, includes an optical element which is arranged in the laser beam converging toward the focal point and which is designed to outcouple a reflection from the laser beam path, and a sensor arrangement which is designed to detect beam characteristics of said laser beam in the region of the focal point in the laser extension direction, and which measures the outcoupled reflection of the laser beam at at least two locations that are offset to one another in the extension direction, in order to determine the current focal position.

According to one embodiment, a light source includes a plurality of light-emitting elements each including one or more surface-emitting lasers; and a plurality of detecting elements located on a same substrate as the light-emitting elements. The detecting elements individually detect quantities of output light of the light-emitting elements.

A gravity-enforced photon momentum radiometer incudes: a magnetic array; a diamagnetic shuttle that levitates above the magnetic array; a mirror on the diamagnetic shuttle that receives laser light and moves the diamagnetic shuttle due to the optical force; a tiltable platform for the magnetic array; a photogate producing gate light that can be blocked by a photo interrupter and that produces a detector signal that provides a position of the diamagnetic shuttle relative to the tiltable platform for determining a position of the diamagnetic shuttle relative to the photogate.

There is provided an optical power measurement method, an offset calibration method and an optical power meter that is adapted to apply the offset calibration method. The optical power measurement method, the offset calibration method and the optical power meter are characterized in that two temperature sensors are used for more accurate predictions of the optical power offset. A first temperature sensor is positioned to read a temperature of the photodiode and a second temperature sensor is positioned to read a temperature of the PCB ground plane.

A system for measuring the power of a laser beam, comprising an essentially opaque enclosure, from which the laser beam is directed through an exit aperture. The enclosure contains a beam splitter configured to transmit a major part of the laser beam through the exit aperture, and to reflect a minor part of the laser beam; a diffuser element positioned such that the reflected minor part of the laser beam impinges thereon; at least one detector element in optical communication with the diffuser element, the detector element providing a signal in response to the diffused light of the minor part of the laser beam impinging thereon; and an absorber element positioned such that that part of any light entering the enclosure through the exit aperture and reflected by the beam splitter, impinges on the absorber element, and is essentially absorbed.

A detector of electromagnetic radiation (RL) is described. The detector comprises: an oriented polycrystalline layer (2) of thermoelectric material, a substrate (1) superimposed on the top surface of the oriented polycrystalline layer so that the back surface (10) is in contact with the oriented polycrystalline layer, first and second electrodes spaced the one from the other and in electrical contact with the oriented polycrystalline layer. The substrate comprises at least one ceramic layer and the oriented polycrystalline layer has a crystal orientation at an angle comprised between 30 degrees and 55 degrees relative to a normal to the top surface of the substrate.

Methods and systems for determining one or more characteristics of light in an optical system are provided. One system includes first detector(s) configured to detect light having one or more wavelengths shorter than 190 nm emitted from a light source at one or more first angles mutually exclusive of one or more second angles at which the light is collected from the light source by an optical system for illumination of a specimen and to generate first output responsive to the light detected by the first detector(s). In addition, the system includes a control subsystem configured for determining one or more characteristics of the light at one or more planes in the optical system based on the first output.

Systems and methods are disclosed for monitoring a laser system using detection of back reflection. In some embodiments, a laser system comprises a laser, at least one optical fiber, and a back-reflection monitoring sensor for detecting electromagnetic radiation reflected back from the optical fiber(s). The back-reflection monitoring sensor may be adapted to detect back-reflected electromagnetic radiation while the laser system is in use. The laser system may further comprise a computing system adapted to calculate an output power of the system based upon the back-reflected electromagnetic radiation. In some embodiments, a method of monitoring a laser system using detection of back reflection comprises transmitting electromagnetic radiation from a laser, receiving the electromagnetic radiation at one or more optical fibers, and detecting electromagnetic radiation that is back reflected at a back-reflection monitoring sensor.

A lamination molding apparatus includes a molding room, a chamber, a chamber window, a molding table, a molding table driving device, surrounding walls, an irradiation device, a measuring unit, and a controller. The measuring unit includes a first measuring device acquiring a measured value of a light intensity, and a second measuring device acquiring a value of a beam diameter, and measures laser beams outputted based on set values of light intensity during molding. The controller determines an abnormality has occurred when a slope of a linear function obtained from a relationship between the measured value of the light intensity and the value of the beam diameter at a predetermined height is out of a predetermined range, or when a slope of a linear function obtained from a relationship between the measured value of the light intensity and a value of a focal position is out of a predetermined range.

The present invention relates to laser beam profiling, more specifically to weak signals which are barely identified on a display screen representing the beam levels by color or gray palettes. Each displayed pixel on a beam profiling image represents the amount of laser power on said pixel. This represents the intensity information on a specific pixel. Integrating the pixel intensity information over the whole image will calculate the total power. Seldom, especially in high resolution cameras, the displayed information is indiscernible on the screen. However, there is enough information to observe the beam profile if the color or grayscale palette is displayed as percentage values of maximum intensity on the screen. Then, each percentage level will be assigned with a different color. By doing that, even very poor levels of displayed images could be enhanced to span over a full color or grayscale palette. The disclosed method is characterized by initially finding the maximum level of an image by histogram, then divide each pixel value by the maximum value found in the histogram, followed by displaying an image which has colors according to the percentage of power of each pixel relative to the maximum histogram level. This procedure can be performed either manually where the user adjusts the palette maximum, or automatically where software finds maximum level on histogram and spans the color palette onto the image percentage from maximum.