Abstract: A method, apparatus, and system are provided to monitor and characterize the dynamics of a phase change region (PCR) created during laser welding, specifically keyhole welding, and other material modification processes, using low-coherence interferometry. By directing a measurement beam to multiple locations within and overlapping with the PCR, the system, apparatus, and method are used to determine, in real time, spatial and temporal characteristics of the weld such as keyhole depth, length, width, shape and whether the keyhole is unstable, closes or collapses. This information is important in determining the quality and material properties of a completed finished weld. It can also be used with feedback to modify the material modification process in real time.

Abstract: The disclosed ultra-high power all fiber laser system is configured with multiple spaced apart fiber lasers outputting respective laser beams respective paths. The disclosed system is further configured with a tapered fiber-bundle including at least one central guiding fiber and a plurality of peripheral guiding fibers. The disclosed system further has a multiclad delivery fiber configured with a double-bottle neck cross-section and provided with at least two concentric and radially spaced apart inner and outer cores. The inner core is coupled to the peripheral guiding fibers while the inner core is spliced to the central guiding fiber so that a system output emitted from the inner core of the delivery fiber has a different beam shape from the system output emitted from the outer core.

Abstract: An optical parametric device (OPD), which is selected from an optical parametric oscillator (OPO) or optical parametric generator (OPG), is configured with a nonlinear optical element (NOE) which converts an incoupled pump radiation at first frequency into output signal and idler radiations at one second frequency or different second frequencies, which is/are lower than the first frequency, by utilizing nonlinear interaction via a random quasi-phase matching process (RQPM-NOE). The NOE is made from a nonlinear optical material selected from optical ceramics, polycrystals, micro and nanocrystals, colloids of micro and nanocrystals, and composites of micro and nanocrystals in polymer or glassy matrices. The nonlinear optical material is prepared by modifying a microstructure of the initial sample of the NOE such that an average grain size is of the order of a coherence length of the three-wave interaction which enables the highest parametric gain achievable via the RQPM process.

Abstract: A surface treating method and apparatus include operating a quasi-continuous wave fiber laser and pre-scan shaping the laser beam such that an instantaneous spot beam has predetermined geometrical dimensions, intensity profile, and power; operating a scanner at an optimal angular velocity and angular range to divide the pre-scan beam into at least one sub-beam deflected toward the surface being processed; guiding the sub-beam through a post-scan optical assembly to provide the spot beam with predetermined geometrical dimensions, power, and angular velocity and range, which are selected such that the instantaneous spot beam is dragged in a scan direction over a desired length at a desired scan velocity, which allow the treated surface to be exposed for a predetermined exposure duration and have a predetermined fluence distribution providing the treated surface with a quality comparable to that of the surface processed by an excimer laser or a burst-mode fiber laser.

Abstract: An endoscopic device having reduced cross-section and a steering section of enhanced compliance. The device defines a smaller cross-section by eliminating need for pull wires and torsion sleeves. Use of a single fiber optic for steering opens up cross-sectional space to augment both irrigation and aspiration channels within a common catheter shaft. The single fiber optic may be utilized for “pulling” and/or “pushing” on the steering section, thereby providing unidirectional or bidirectional steering with a single fiber or fiber bundle. A distal steering section is configured to enhance compliance in response to the forces exerted by the single fiber optic. The enhanced compliance reduces the stoutness required of the fiber optic enabling a reduction in the size of the single fiber optic, thereby freeing up cross-section of the catheter for other uses. The enhanced compliance also enables tighter and more predictable articulation for better steering dexterity.

Abstract: A laser system that includes a processing laser configured to generate a laser beam, a beam delivery system configured to direct the laser beam at a target, a user input device configured to receive input from a user, and a controller coupled to the processing laser and the user input device and configured to: receive initial user input data from the user input device, the initial user input data including at least one of: one or more properties of the beam delivery system, and one or more properties of the target, determine at least one initial laser operating parameter value and a corresponding initial laser operating parameter range based on the initial user input data, and electronically stored information, and control the processing laser using the at least one initial laser operating parameter value.

Abstract: A device for performing treatment of biological tissue that includes a laser system configured to provide a laser beam having a wavelength within a range of 3.0 microns (?m) to 3.25 ?m inclusive and a spot size within a range of 10 ?m to 45 ?m inclusive, and a controller coupled to the laser system and configured to scan the laser beam over the biological tissue in an injury pattern, the injury pattern having a pitch that is sized to be in a range of 0.1 mm to 1 mm inclusive.

Abstract: A method for controlling a surgical laser system that includes providing a surgical fiber configured to receive light reflected from a target in a surgical treatment area, and providing a computing device configured to couple with at least two photodetectors, each photodetector configured to detect an intensity of reflected light from the target in a different selected wavelength band, the computing device further configured to: receive the reflected light intensity in at least two selected wavelength bands, generate optical data corresponding to the reflected light intensity, and identify the target as a treatment target or a non-treatment target based at least in part on the optical data and a predetermined calibration based on at least two known targets.

Abstract: A system for controlling pressure within a kidney that includes an irrigation channel configured with a pressure sensor, a distal end of the irrigation channel in fluid communication with an interior of a kidney, an aspiration channel in fluid communication with a drain reservoir, a distal end of the aspiration channel in fluid communication with the interior of the kidney, and a controller configured to: determine a fluid flow rate of irrigation fluid within the irrigation channel and receive a pressure measurement value from the sensor, calculate a pressure within the interior of the kidney based at least in part on the determined fluid flow rate and the pressure measurement, compare the calculated kidney pressure to a target kidney pressure value, and based on the comparison, control at least one of the fluid flow rates of irrigation fluid in the irrigation channel and the aspiration channel.

Abstract: A system and method may be used to monitor and/or control material processing where a process beam is moved in a wobble pattern, such as a wobble-welding process. While at least one process beam is moved according to a wobble pattern on a processing site (e.g., a weld site) of a workpiece, an ICI system moves an imaging beam at least partially independently of the process beam to one or more measurement locations on the wobble pattern and obtains ICI measurements (e.g., depth measurements) at those locations. The ICI measurement(s) may be used, for example, to evaluate keyhole and/or melt pool characteristics during a welding process. Although the present application describes wobble welding processes, the systems and methods described herein may also be used with other material processing applications where a laser or other energy beam is wobbled or dithered during processing including, without limitation, additive manufacturing, marking and material removal.

Abstract: A nozzle assembly for performing material processing operations with a handheld laser system on a surface of a workpiece. The handheld laser system comprises a laser source configured to generate laser radiation, a handheld device that guides the laser radiation, and an optical fiber coupling the handheld device to the laser source, and the nozzle assembly comprises a nozzle configured to deliver the laser radiation to the surface, and a coupling mechanism that includes a retaining portion formed on an output end of the handheld device, and an engagement portion configured to be releasably attachable to the nozzle and engage with the retaining portion.

Abstract: A laser welding head with movable mirrors may be used to perform welding operations, for example, with wobble patterns and/or seam finding/tracking and following. The movable mirrors provide a wobbling movement of one or more beams within a relatively small field of view, for example, defined by a scan angle of 1-2°. The movable mirrors may be galvanometer mirrors that are controllable by a control system including a galvo controller. The laser welding head may also include a diffractive optical element to shape the beam or beams being moved. The control system may also be used to control the fiber laser, for example, in response to the position of the beams relative to the workpiece and/or a sensed condition in the welding head such as a thermal condition proximate one of the mirrors.

Abstract: Systems, methods and apparatuses are used for monitoring material processing using imaging signal density calculated for an imaging beam directed to a workpiece or processing region, for example, during inline coherent imaging (ICI). The imaging signal density may be used, for example, to monitor laser and e-beam welding processes such as full or partial penetration welding. In some examples, the imaging signal density is indicative of weld penetration as a result of reflections from a keyhole floor and/or from a subsurface structure beneath the keyhole. The monitoring may include, for example, automated pass/fail or quality assessment of the welding or material processing or parts produced thereby. The imaging signal density may also be used to control the welding or material processing, for example, using imaging signal density data as feedback. The imaging signal density may be used alone or together with other measurements or metrics, such as distance or depth measurements.

Abstract: A laser system includes a high voltage AC-to-DC power converter and one or more current sources coupled to the power converter without a DC-to-DC converter between the current sources and the power converter. Each of the current sources includes a high voltage switch and one or more independent safety shutoffs. A laser module is operably coupled to the one or more current source and configured to emit electromagnetic radiation wherein the one or more safety shutoffs are configured to disable emission of electromagnetic radiation from the laser module when triggered. A current source controller coupled to the safety shutoff(s) is configured to generate enabling signals that enable normal current source operation. The controller includes circuitry configured to measure power across the high voltage switch when the controller instructs the high voltage switch to turn off to determine proper operation of the safety shutoff(s).

Abstract: Systems and methods may be used to monitor and/or control a short-pulse laser welding process involving the formation of a series of heat stakes in the welded materials. The systems and methods use an imaging system, such as an ICI system, capable of obtaining measurements inside the vapor channels during formation of the heat stakes and thus provide stake measurement data representing characteristics of the stakes. The stake measurement data may be used to monitor and/or control the short-pulse laser welding process.

Abstract: An irrigation and aspiration system that includes a catheter shaft having a distal end that is in fluid communication with an interior of a kidney, an irrigation channel and an aspiration channel extending through the shaft, a bypass channel fluidly coupled with the irrigation channel and the aspiration channel a bypass valve configured to control a level of fluid communication between the irrigation and aspiration channels via the bypass channel, an aspiration pump, at least one valve disposed on the aspiration channel and configured to provide a pulsed flow of fluid in the aspiration channel, a pressure sensor in fluid communication with an interior of the kidney, and a controller configured to: receive at least one pressure measurement, compare the measured pressure to a threshold, and based on the comparison, send a control command to at least one of the bypass valve, aspiration pump, and the at least one valve.

Abstract: A method and system for cleaning a surface using laser radiation is provided. In one example, a system for cleaning a surface using laser radiation includes a laser source configured to generate laser radiation, the laser source configured to emit laser radiation in a cleaning mode, the cleaning mode characterized as a modulated continuous wave (CW) mode having a duty cycle less than 110%, pulse-repetition frequency greater of at least 10 kilohertz (kHz), and a FWHM pulse duration in a range of 1 microsecond (?s) to 10 (milliseconds) ms inclusive, a housing configured as a handheld apparatus that directs the later radiation to the surface, and an optical fiber coupling the handheld apparatus to the laser source.

Abstract: A multiple wavelength laser processing system is configured with a multiple wavelength laser source for generating a multiple wavelength coaxial laser processing beam. The laser processing system further includes a multiple wavelength optical system to deliver the coaxial laser processing beam to a laser-material interaction zone on the surface of a workpiece such that each of the a first and a second laser wavelengths in the processing beam impinge at least a portion of the interaction zone as respective first and second concentric laser spots. The multiple wavelength optical system includes a multiple wavelength beam collimator, a configurable chromatic optic, and a laser processing focus lens, wherein the configurable chromatic optic provides an adjustment to the relative focus distance of the first and second laser wavelengths.