82 results about "Optical breakdown" patented technology

A system and method are provided for fragmenting a crystalline lens, to facilitate its removal from the lens bag during an ophthalmic laser surgery. First, a predetermined pattern is used to make Laser Induced Optical Breakdown (LIOB) cuts that section the lens into asymmetrical, operational segments. At least one operational segment is then selected and softened with a plurality of compact LIOB cuts. Once softened, the selected segment is aspirated. The remaining operational segments are then subsequently removed. During a procedure, an imaging unit can monitor movements of the lens bag to ensure proper placement of the LIOB cuts on the lens.

Systems and methods are described for forming continuous laser filaments in transparent materials. A burst of ultrafast laser pulses is focused such that a beam waist is formed external to the material being processed without forming an external plasma channel, while a sufficient energy density is formed within an extended region within the material to support the formation of a continuous filament, without causing optical breakdown within the material. Filaments formed according to this method may exhibit lengths exceeding up to 10 mm. In some embodiments, an aberrated optical focusing element is employed to produce an external beam waist while producing distributed focusing of the incident beam within the material. Various systems are described that facilitate the formation of filament arrays within transparent substrates for cleaving/singulation and/or marking. Optical monitoring of the filaments may be employed to provide feedback to facilitate active control of the process.

Systems and methods are described for forming continuous curved laser filaments in transparent materials. The filaments are preferably curved and C-shaped. Filaments may employ other curved profiles (shapes). A burst of ultrafast laser pulses is focused such that a beam waist is formed external to the material being processed without forming an external plasma channel, while a sufficient energy density is formed within an extended region within the material to support the formation of a continuous filament, without causing optical breakdown within the material. Filaments formed according to this method may exhibit lengths in the range of 100 μm-10 mm. An aberrated optical focusing element is employed to produce an external beam waist while producing distributed focusing of the incident beam within the material. Optical monitoring of the filaments may be employed to provide feedback to facilitate active control of the process.

An acoustic monitoring method and system in laser-induced optical breakdown (LIOB) provides information which characterize material which is broken down, microbubbles in the material, and/or the microenvironment of the microbubbles. In one embodiment of the invention, femtosecond laser pulses are focused just inside the surface of a volume of aqueous solution which may include dendrimer nanocomposite (DNC) particles. A tightly focused, high frequency, single-element ultrasonic transducer is positioned such that its focus coincides axially and laterally with this laser focus. When optical breakdown occurs, a microbubble forms and a shock or pressure wave is emitted (i.e., acoustic emission). In addition to this acoustic signal, the microbubble may be actively probed with pulse-echo measurements from the same transducer. After the microbubble forms, received pulse-echo signals have an extra pulse, describing the microbubble location and providing a measure of axial microbubble size. Wavefield plots of successive recordings illustrate the generation, growth, and collapse of microbubbles due to optical breakdown. These same plots can also be used to quantify LIOB thresholds.

A device for calibrating a laser beam system includes a calibration member having a surface positioned at a predetermined distance from the base datum of the unit. Further, the system includes a mechanism for focusing the beam to a focal point and for moving the focal point relative to the surface of the calibration member. When the focal point reaches the surface of the calibration member, Laser Induced Optical Breakdown (LIOB) is induced. Thereafter, the position of the location of LIOB may be measured relative to the base datum to calibrate the laser beam. Further, patterns may be applied to the calibration member using LIOB to calibrate tilt/decenter of the beam and to determine the energy density and uniformity in the focal spot of the laser beam.

This invention discloses a method of producing, in a solid transparent material (3), a hologram of an object; the method includes the steps of: developing a three-dimensional mathematical model of an electro-magnetic field emanating from the object, the field producing an image of the object; computing a corresponding three-dimensional set of points, light scattered from which reconstructs the field; and focusing a pulsed laser beam into the solid transparent material onto each of the points sequentially, the beam being capable, when focused, of causing optical breakdown in the solid transparent material.

A light based skin treatment device (10, 20) is provided, comprising a light source (18) for providing an incident light beam (21) for treating a skin (30) by laser induced optical breakdown (LIOB) of hair or skin tissue, a transparent exit window (14) for allowing the incident light beam (21) to exit the device (10, 20), and an optical system for focusing the incident light beam (21) into a focal spot (221, 222) in the hair or skin tissue outside the skin treatment device (10, 20). The exit window (14) comprises an outer surface (41, 42, 43, 44) having optical scattering properties such that, for a predetermined power and pulse duration of the incident light beam (21), when the outer surface (41, 42, 43, 44) is in contact with a medium having a refractive index equal to a refractive index (n1) of the exit window (14), a dimension of the focal spot is sufficiently small for a power density of the incident light beam (21) in the focal spot to exceed a threshold value for inducing a LIOB phenomenon in the focal spot, and when the outer surface (41, 42, 43, 44) is in contact with a medium having a refractive index equal to a refractive index (n2) of air, a dimension of the focal spot is sufficiently large for a power density of the incident light beam (21) in the focal spot not to exceed the threshold value for inducing a LIOB phenomenon in the focal spot.

By adapting femtosecond micromachining approaches developed in hydrogels, we can perform Intra-tissue Refractive Index Shaping (IRIS) in biological tissues. We reduced femtosecond laser pulse energies below the optical breakdown thresholds to create grating patterns that are associated with a change in the refractive index of the tissue. To increase two-photon absorption, we used a two (or more)-photon-absorbing chromophore.

A system for changing the configuration of a transparent, resilient material, for the purpose of altering its optical properties, requires obtaining a topology for the material. The obtained data is then used to create a computer program for operating a laser unit. In accordance with the program, the laser unit creates incisions within a defined operational volume, inside the material, to weaken the material (i.e. change its internal stress distributions). Specifically, the incisions are made on predetermined surfaces (e.g. cylindrical surfaces) in the operational volume by Laser Induced Optical Breakdown (LIOB). As a consequence of the incisions, the material undergoes the desired configurational change in response to external forces applied on the material.

A system and method are provided for an ophthalmic surgical procedure to provide a refractive correction for an eye. Specifically, the procedure is indicated when the desired refractive correction “d_reqd” exceeds the capability of a correction achievable when corneal tissue is only ablated. In accordance with the present invention, an optimized refractive correction “d₁” is accomplished by the ablation of corneal tissue (e.g. by a PRK or LASIK procedure). The optimized correction is then followed by a complementary refractive correction “d₂” wherein stromal tissue is weakened with Laser Induced Optical Breakdown (LIOB). Together, the optimized refractive correction (ablation) and the complementary refractive correction (LIOB) equal the desire refractive correction (d_reqd=d₁+d₂).

A device for treating skin, the gums, a tooth, or an internal organ by a laser pulse source for generating laser pulses with a pulse duration which is preferably in the femtosecond range, and an optical path for directing the laser pulses from the laser pulse source for the surface of the skin, gums, tooth or internal organ. The laser pulses are directed onto the surface of the skin, gums, tooth or the internal organ in such a way that the pulses are focused in the skin, in the gums, in the tooth or in the internal organ and cause a laser-induced optical breakdown below the surface of the respective skin, gums, tooth or internal organ, whereat the laser pulses have a larger cross-sectional area at the surface of the skin, of the gums, the tooth or of the internal organ than at the location of the laser-induced optical breakdown.

A method for producing, trapping and manipulating a gas microbubble in liquid is disclosed. The method includes providing a pulsed laser source for generating a pulsed laser radiation and focusing optics; and focusing a pulsed laser radiation to a focal zone within the liquid, with energy exceeding the threshold of optical breakdown in the liquid at the focal zone. It is also suggested to use focusing optics to focus the laser beam to a focal point at a depth close to the compensation depth of the focusing optics for spherical aberration.

A system and method for performing Laser Induced Optical Breakdown (LIOB) on a target tissue includes a detector for imaging the interface surface between the target tissue and a base tissue. Also included is a laser unit for generating a laser beam, and for focusing the laser beam to a focal point. A computer is provided for controlling movement of the focal point. Specifically, this control is accomplished to maintain the focal point in the target tissue, but beyond a predetermined distance from the interface surface. For the present invention, the predetermined distance is established by considerations of laser beam geometry, which are applied in the context of images that are created of the interface surface.

A method of producing in a solid transparent material, a diffractive optical element for the transformation of an incident wave in a predefined manner, by developing a mathematical model of the element in terms of the required transformation, then using that model for determining a set of points which form the desired diffractie optical element, and then focusing a pulsed laser beam sequentially onto the points in the set, such that it causes optical breakdown damage at those points. Numerical solutions for determining the positions of the set of points from the mathematical model are presented. The production of number of elements for specific applications is described. Complete laser systems capable of monitoring the production of the points in real time according to the results obtained by diffraction of the incident wave by the element under production.

A system (101) for treatment of an epithelial tissue layer (3) is provided. The system comprises a reservoir (107), for containing an amount of a flowable medium, arranged to enable the medium, when contained in the reservoir, to be in contact with a surface (5) of the epithelial tissue layer, a light source (109) for generating a laser beam (11) during at least a predetermined pulse time, and an optical system for focusing the laser beam into a focal spot (15), and for positioning the focal spot in a target position. The target position of the focal spot is within the reservoir and within the medium, when contained in the reservoir, and the dimension of the focal spot and the power of the generated laser beam are such that, in the focal spot, the laser beam has a power density, which is above the characteristic threshold value for the medium, above which, for the predetermined pulse time, a laser induced optical breakdown event occurs in the medium. A method for treatment of an epithelial tissue layer is also provided.

A system and method for performing a femto-fragmentation procedure on tissue in the crystalline lens of an eye requires that a laser beam be directed and focused to a focal point in the crystalline lens of the eye. The focal point is then guided, relative to an axis defined by the eye, to create a segment cluster by causing Laser Induced Optical Breakdown (LIOB) of tissue in the crystalline lens. The resultant segment cluster includes a plurality of contiguous, elongated segments in the crystalline lens that are individually tapered from an anterior end-area to a posterior end-area. Specifically, this is done to facilitate the removal of individual segments from the segment cluster in the crystalline lens.

A system and method for altering the configuration of a transparent material (e.g. the cornea of an eye) requires identifying local stress distribution patterns inside the material. These patterns are then used to define boundary (interface) surfaces between volumes within the material. In operation, a laser unit performs Laser Induced Optical Breakdown (LIOB) along selected boundary surfaces to disrupt stress distribution patterns between volumes of the material that are separated from each other by the boundary surface. This LIOB allows an externally applied force to thereby alter the configuration of the material.

The invention provides a non-invasive device (100) for treatment of skin tissue using laser light, and it provides a method and a computer program product. The non-invasive device comprises a light emission system (110) for generating a first laser pulse (130) and a subsequent second laser pulse (150) at a predefined time delay (ΔT) after the first laser pulse. The non-invasive device further comprises an optical system (160) for focusing, in use, the first laser pulse and the second laser pulse at a treatment location (210) inside the skin tissue (200). The first laser pulse comprises a first power density, a first pulse duration and a first pulse energy for initiating a plasma (205) at the treatment location. The subsequent second laser pulse comprises a second power density being lower than the first power density and a second pulse duration being at least 10 times longer than the first pulse duration, and a second pulse energy higher than the first pulse energy for sustaining or intensifying the plasma initiated by the first laser pulse, whereby in use the first laser pulse and the second laser pulse together induce Laser Induced Optical Breakdown at the treatment location.