Abstract: The present application discloses a method and apparatus for compensation of focal errors in laser beam measurement instruments that characterize beam parameters by analyzing images of Rayleigh scatter taken at multiple angles around the beam axis. If the laser beam is not precisely positioned, these images may not be in focus, and the instrument will not report accurate results. This method and apparatus finds the longitudinal axis of the beam by analyzing the beam location in at least two images. All images are subdivided into slices and distances from the beam axis to the focal plane for each slice are calculated and used to find an out-of-focus transfer function for each slice, which is used in combination with the modulation transfer function of the system to deconvolve the slice. Images formed by reassembling the deconvolved slices can then be analyzed to obtain the correct beam parameters.

Abstract: The present application discloses a zoom lens assembly having a first static lens group and a second static lens group defining an assembly optical axis secured to a lens support. A first guide member having a first guide member axis is secured to the lens support, and a second guide member having a second guide member axis is secured to the first guide member. A first mobile carriage is slidably coupled to the first guide member and a first mobile lens cell having a first optical axis is secured to the first mobile carriage. A second mobile carriage is slidably coupled to the first guide member, with a second mobile lens cell having a second optical axis secured to the second mobile carriage. The zoom lens assembly further includes a third mobile carriage slidably coupled to the second guide member, with a third mobile lens cell having a third optical axis secured to the third mobile carriage.

Abstract: The present application discloses an apparatus configured to measure characteristics of high power beams of laser energy used in material processing. In one embodiment, the apparatus includes a housing having a first compartment and a second compartment separated from each other to reduce the transfer of thermal energy between them. Optical modules having optical sensors configured to measure characteristics of the high power beam are mounted in the first compartment. An optical window operative to allow a significant portion of the beam to propagate therethrough is mounted in an intermediate housing member separating the first and second compartments. A removable and replaceable beam dump configured to absorb most of the high power beam is positioned in the second compartment. The removability/replaceability of the beam dump enables operation of the apparatus without active cooling of the beam dump assembly, simplifying the apparatus and protecting the optical sensors in the first compartment.

Abstract: The present application discloses an improved thermopile laser sensor apparatus and methods of use. In one embodiment, the apparatus includes a sensor body having a first sensor body recess and a second sensor body recess formed therein, with a substrate positioned in the first sensor body recess in thermal communication with the sensor body. The substrate includes at least one absorber attached thereto and configured to absorb a portion of a beam of laser energy. A first thermal sensor in thermal communication with the substrate and the sensor body may be formed on or attached to the substrate. A second thermal sensor in thermal communication with the sensor body may be positioned in the second sensor body recess. A thermal barrier configured to reduce the rate of transfer of thermal energy from the substrate to the second thermal sensor may be positioned between the substrate and the second thermal sensor.

Abstract: The present application discloses a zoom lens assembly having a first static lens group and a second static lens group defining an assembly optical axis secured to a lens support. A first guide member having a first guide member axis is secured to the lens support, and a second guide member having a second guide member axis is secured to the first guide member. A first mobile carriage is slidably coupled to the first guide member and a first mobile lens cell having a first optical axis is secured to the first mobile carriage. A second mobile carriage is slidably coupled to the first guide member, with a second mobile lens cell having a second optical axis secured to the second mobile carriage. The zoom lens assembly further includes a third mobile carriage slidably coupled to the second guide member, with a third mobile lens cell having a third optical axis secured to the third mobile carriage.

Abstract: The present application discloses an apparatus configured to measure characteristics of high power beams of laser energy used in material processing. In one embodiment, the apparatus includes a housing having a first compartment and a second compartment separated from each other to reduce the transfer of thermal energy between them. Optical modules having optical sensors configured to measure characteristics of the high power beam are mounted in the first compartment. An optical window operative to allow a significant portion of the beam to propagate therethrough is mounted in an intermediate housing member separating the first and second compartments. A removable and replaceable beam dump configured to absorb most of the high power beam is positioned in the second compartment. The removability/replaceability of the beam dump enables operation of the apparatus without active cooling of the beam dump assembly, simplifying the apparatus and protecting the optical sensors in the first compartment.

Abstract: The present application discloses a zoom lens assembly utilizing a novel extension spring configured to exert a biasing force on one or more lens cells during operation thereof. In one embodiment, the extension spring includes a spring body having a coil axis, a first spring end region having a first inner coil and a first outer coil formed on the spring body, wherein the coil axis of the spring body transitions from the first inner coil to the first outer coil. The extension spring further includes a second spring end region having a second inner coil and a second outer coil formed on the spring body, wherein the coil axis of the spring body transitions from the second inner coil to the second outer coil. An intermediate spring region having a plurality of intermediate coils extends from the first spring end region to the second spring end region.

Abstract: A power measuring sensor for an optical beam which utilizes the temperature difference across a thin layer of heat insulating material, generated by the axial flow of the absorbed beam, from an absorber layer on which the beam impinges, to a cooled heat sink which dissipates the heat after passage through the sensor. The axial heat flow is measured by means of a continuous matrix of adjacent thermocouple junctions over the heat flow region of the sensor disc, with the thermal insulating layer, which generates the temperature drop, having thicker and thinner regions at alternate junctions. The junctions on the thicker regions of the insulator thus become the hot junctions, and those on the thinner regions of the insulating layer become the cold junctions, and the sum of the voltages generated by the thermocouples is proportional to the flow of heat, and thus to the incident optical power.

Abstract: A laser power meter incorporating an absorber disc with a peripheral thermopile ring, either continuous or segmented, and an additional temperature detection element in the central portion, that enables measurement of beam size. This detection element can be a thermopile element, generally a ring of smaller diameter than the peripheral thermopile used, and located closer to the center of the absorber disc. With this arrangement the beam size can be measured, in addition to measurements of the power and the position of the beam. Alternatively, this centralized detection element can be a single thermocouple junction located at the center of the disc, which acts as the hot junction of a thermocouple pair. The second or cold junction is effectively located on the disc close to the peripheral thermopile. Alternatively, two temperature measuring elements can be used, one at the disc center and one at the periphery.

Abstract: A power measuring sensor for an optical beam which utilizes the temperature difference across a thin layer of heat insulating material, generated by the axial flow of the absorbed beam, from an absorber layer on which the beam impinges, to a cooled heat sink which dissipates the heat after passage through the sensor. The axial heat flow is measured by means of a continuous matrix of adjacent thermocouple junctions over the heat flow region of the sensor disc, with the thermal insulating layer, which generates the temperature drop, having thicker and thinner regions at alternate junctions. The junctions on the thicker regions of the insulator thus become the hot junctions, and those on the thinner regions of the insulating layer become the cold junctions, and the sum of the voltages generated by the thermocouples is proportional to the flow of heat, and thus to the incident optical power.