3104 results about "Femtosecond" patented technology

The present invention relates to the apparatus, system and method for dicing of semiconductor wafers using an ultrafast laser pulse of femtosecond and picosecond pulse widths directly from the ultrafast laser oscillator without an amplifier. Thin and ultrathin simiconductor wafers below 250 micrometer thickness, are diced using diode pumped, solid state mode locked ultrafast laser pulses from oscillator without amplification. The invention disclosed has means to avoid/reduce the cumulative heating effect and to avoid machine quality degrading in multi shot ablation. Also the disclosed invention provides means to change the polarization state of the laser beam to reduce the focused spot size, and improve the machining efficiency and quality. The disclosed invention provides a cost effective and stable system for high volume manufacturing applications. An ultrafast laser oscillator can be a called as femtosecond laser oscillator or a picosecond laser oscillator depending on the pulse width of the laser beam generated.

Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. In at least one embodiment, an ultrashort pulse laser system may include at least one of a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may also include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond and/or picosecond pulses, and in some embodiments with pulse widths up to a few nanoseconds.

Optical coherence tomography (OCT) is used to map the surface elevation and thickness of the cornea. The OCT maps are used to plan laser procedures for the treatment of an irregular, opacified or weakened cornea, and in the treatment of refractive errors. In the excimer laser phototherapeutic keratectomy (PTK) procedure, the OCT data is used to plan a map of ablation depth needed to restore a smooth optical surface. In the excimer laser photorefractive keratectomy procedure, OCT mapping of epithelial thickness is used to achieve clean laser epithelial removal. In femtosecond laser anterior keratoplasty procedure, OCT data is used to plan the depth of femtosecond laser dissection to remove an anterior layer of the cornea, leaving a smooth recipient bed of uniform thickness to receive a disk of donated corneal tissue. The linkage of an OCT system to a precise laser surgical system enables the performance of new procedures that are safer, less invasive and produce faster visual recovery than conventional surgical procedures.

Powerful nanosecond-range lasers using low repetition rate pulsed laser deposition produce numerous macroscopic size particles and droplets, which embed in thin film coatings. This problem has been addressed by lowering the pulse energy, keeping the laser intensity optional for evaporation, so that significant numbers of the macroscopic particles and droplets are no longer present in the evaporated plume. The result is deposition of evaporated plume on a substrate to form thin film of very high surface quality. Preferably, the laser pulses have a repetition rate to produce a continuous flow of evaporated material at the substrate. Pulse-range is typically picosecond and femtosecond and repetition rate kilohertz to hundreds of megahertz. The process may be carried out in the presence of a buffer gas, which may be inert or reactive, and the increased vapour density and therefore the collision frequency between evaporated atoms leads to the formation of nanostructured materials of increasing interest, because of their peculiar structural, electronic and mechanical properties. One of these is carbon nanotubes, which is a new form of carbon belonging to the fullerene (C60) family. Carbon nanotubes are seamless, single or multishell co-axial cylindrical tubules with or without dome caps at the extremities. Typically diameters range from 1 nm to 50 nm with a length >1 mum. The electronic structure may be either metallic or semiconducting without any change in the chemical bonding or adding of dopant. In addition, the materials have application to a wide range of established thin film applications.

Improved devices, systems, and methods for diagnosing, planning treatments of, and/or treating the refractive structures of an eye of a patient incorporate results of prior refractive corrections into a planned refractive treatment of a particular patient by driving an effective treatment vector function based on data from the prior eye treatments. The exemplary effective treatment vector employs an influence matrix which may allow improved refractive corrections to be generated so as to increase the overall accuracy of laser eye surgery (including LASIK, PRK, and the like), customized intraocular lenses (IOLs), refractive femtosecond treatments, and the like.

Methods and systems for laser-based processing of materials are disclosed wherein a scalable laser architecture, based on planar waveguide technology, provides for pulsed laser micromachining applications while supporting higher average power applications like laser welding and cutting. Various embodiments relate to improvements in planar waveguide technology which provide for stable operation at high powers with a reduction in spurious outputs and thermal effects. At least one embodiment provides for micromachining with pulsewidths in the range of femtoseconds to nanoseconds. In another embodiment, 100W or greater average output power operation is provided for with a diode-pumped, planar waveguide architecture.

A method and an apparatus for laser marking indicia in the volume of gemstones such as diamonds, the indicia being made up of a plurality of microscopic dot-shaped marks whose build-up can be initiated by exposing naturally-occurring internal defects or impurities in the volume of a gemstone to a tightly focused train of laser pulses. Authentication data is encoded in the gemstone from the relative spatial arrangement of the dot-shaped marks that form the indicium. Taking advantage of the presence of otherwise invisible defects in the gemstone allows for inscribing indicia with laser pulses carrying energies substantially lower than the threshold energy required for inscribing in the volume of a perfect gemstone material. The marking process is then much less susceptible to inflict damages to the surface of the gemstone, and the marking can be performed using a broad variety of femtosecond laser systems. The dot-shaped marks engraved at a depth below the surface of a gemstone can be made undetectable with the unaided eye or with a loupe by limiting their individual size to a few micrometres, while devising indicia made up of only a few marks. As a result, the marking does not detract from the appearance and value of the gemstone. The procedure for laser marking accounts for the random spatial distribution of the defects present in natural gemstones as well as for their strongly localized character. The presence of an indicium can be detected by using a dedicated optical reader that can be afforded by every jewellery store.

The invention relates to the technical field of micro-structural surface preparation and laser micro-processing, and in particular provides a method for preparing a micro-nano composite texturing cutting tool by using femtosecond laser. In the method, micro-nano texturing and micro/nano composite texturing preparation is performed on the cutting tool surface by utilizing the unique interaction property between femtosecond laser and materials, the operation is simple, and the accuracy can be controlled. The preparation of micro/nano composite texture can be performed on a coated cutting tool by adopting a coated surface direct texturing method or a two-step composite texturing method. The method overcomes the defect of singleness of texturing only in micron scale in the conventional cutting tool texturing technology, and can further improve the abrasion resistance of the cutting tool, and prolong the service life of the cutting tool.

Methods and apparatuses for dicing substrates by both laser scribing and plasma etching. A method includes laser ablating material layers, the ablating by a laser beam with a centrally peaked spatial power profile to form an ablated trench in the substrate below thin film device layers which is positively sloped. In an embodiment, a femtosecond laser forms a positively sloped ablation profile which facilitates vertically-oriented propagation of microcracks in the substrate at the ablated trench bottom. With minimal lateral runout of microcracks, a subsequent anisotropic plasma etch removes the microcracks for a cleanly singulated chip with good reliability.

A laser system is provided which selectively excites Raman active vibrations in molecules. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and remote sensing.

A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and a spectrometer. Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal. In yet another aspect of the present invention, a multiphoton intrapulse interference phase scan system and method characterize the spectral phase of femtosecond laser pulses. Fiber optic communication systems, photodynamic therapy and pulse characterization tests use the laser system with additional aspects of the present invention.

The invention provides a laser micro/nano processing system and a laser micro/nano processing method. The system of the invention comprises a laser light source, an optical retardation component, an optical focusing component and a computer-controlled micro mobile station, wherein the laser light source is used for providing a first laser beam having a first wavelength and a second laser beam having a second wavelength, the pulse widths of the first laser beam and the second laser beam range from femtosecond to nanosecond and the first wavelength is different from the second wavelength; the optical retardation component is used for regulating the optical path of the first laser beam or the second laser beam so that the difference between the arrival times of the first laser beam and the second laser beam at a focus is not greater than the level life time for a photochromic material to be processed to be excited to an excited state; the optical focusing component is used for focusing the first laser beam and the second laser beam onto the same focus; and the computer-controlled micro mobile station is used for regulating a photochromic material on the computer-controlled micro mobile station to the focus.

A thin film etching method includes forming a layer on a substrate, aligning a mask having a pattern defined thereon above the layer, and removing a portion of the layer by irradiating the substrate with a femtosecond laser through the mask.

A system and method for detecting anomalies concealed upon a person may include a detection probe having an electromagnetic transmitter and an electromagnetic receiver. The electromagnetic transmitter is configured to emit electromagnetic pulses, while the electromagnetic receiver is configured to sample electromagnetic pulses from the electromagnetic receiver at specified times within a waveform window. The electromagnetic pulses may span the terahertz spectral region of 0.04 to 4 THz. The system may also have optical fibers connected to the electromagnetic transmitter and electromagnetic receiver, wherein femtosecond laser pulses are directed from a source to the electromagnetic transmitter and the electromagnetic receiver by the optical fibers.