The development of nonlinear optical (NLO) borate crystals for generation of visible and UV light is reviewed. We first discussed on the basic principles of laser frequency conversion. Then, we examine the trends in research on NLO crystals. The background and present status of NLO borate crystals are summarized. The main considerations are focused on the discussion of crystals like CsLiB6O10 (CLBO), GdxY1−xCa4O(BO3)3 (GdYCOB) and K2Al2B2O7 (KAB). Properties of related materials like β-BaB2O2 (BBO), LiB3O5 (LBO), KBe2BO3F2 (KBBF), Sr2Be2BO7 (SBBO), CsB3O5 (CBO), GdCa4O(BO3)3 (GdCOB) and YCa4O(BO3)3 (YCOB) are included for comparison. We aim to provide a complete view of developing a new NLO borate material for actual laser applications. This review covers various aspects including the search for new materials, the growth of bulk crystals, the characterization of crystal properties as well as the development of new techniques to overcome obstacles in actual laser application, namely, thermal dephasing and laser-induced damage. Finally, perspectives on NLO borate crystals and all-solid-state UV lasers are evaluated.

Recent development of nonlinear optical borate crystals: key materials for generation of visible and UV light

A number of improvements are provided relating to computer aided surgery utilizing an on tool tracking system. The various improvements relate generally to both the methods used during computer aided surgery and the devices used during such procedures. Other improvements relate to the structure of the tools used during a procedure and how the tools can be controlled using the OTT device. Still other improvements relate to methods of providing feedback during a procedure to improve either the efficiency or quality, or both, for a procedure including the rate of and type of data processed depending upon a CAS mode.

On-board tool tracking system and methods of computer assisted surgery

A cardiac ablation method including the following steps: inserting a treatment catheter into an atrium of a heart, the treatment catheter including an ultrasound emitter; positioning the ultrasound emitter to face heart tissue within the left atrium outside of a pulmonary vein; emitting ultrasound energy from the ultrasound emitter while rotating the ultrasound emitter about a rotation axis; and ablating heart tissue with the ultrasound energy to form a lesion outside of a pulmonary vein.

Method for ablating body tissue

A number of improvements are provided relating to computer aided surgery. The improvement relates to both the methods used during computer aided surgery and the devices used during such procedures. Some of the improvement relate to controlling the selection of which data to display during a procedure and/or how the data is displayed to aid the surgeon. Other improvements relate to the structure of the tools used during a procedure and how the tools can be controlled automatically to improve the efficiency of the procedure. Still other improvements relate to methods of providing feedback during a procedure to improve either the efficiency or quality, or both, for a procedure.

Method and apparatus for computer aided surgery

There are disposed two homogenizers for controlling an irradiation energy density in the longitudinal direction of a laser light transformed into a linear one which is inputtted into the surface to be irradiated. Also, there is disposed one homogenizer for controlling an irradiation energy density in a width direction of the linear laser light. According to this, the uniformity of laser annealing can be improved by the minimum number of homogenizers.

Laser irradiation apparatus

A solid state laser system producing coherent radiations at deep ultraviolet wavelengths includes a solid state laser producing a first beam having a wavelength near 1 micron. The 1 micron beam is passed to both a harmonic generation stage and to a tunable optical parametric oscillator. The harmonic generation stage is configured to produce a fifth harmonic of the 1 micron beam, while the optical parametric oscillator produces a tunable beam in the near infrared spectrum (e.g., approximately 2.075 micron). The fifth harmonic and the near infrared beams are mixed in a sum frequency generator to produce a highly coherent beam in the deep ultraviolet (e.g., between approximately 180 nm to 213 nm).

Ultraviolet solid state laser, method of using same and laser surgery apparatus

A laser via drilling system, and a method of use thereof, is provided. The apparatus uses two or more laser systems to achieve processing parameter flexibility. The output beams from the independently controlled laser systems are combined using a beam splitter that combines the beams into single or multiple processing beams. The operational flexibility of the system can be further enhanced through the use of multiple EO modulators and a polarization sensitive beam splitter.

Use of multiple laser sources for rapid, flexible machining and production of vias in multi-layered substrates

Apparatus and method for spectral-beam combining light from a plurality of high-power fiber lasers that, in some embodiments, use two substantially identical diffraction gratings in a parallel, mutually compensating configuration to combine a plurality of separate parallel input beams each having a slightly different successively higher wavelength into a single output beam of high quality. In other embodiments, a single diffraction grating is used to combine a plurality of different wavelengths, wherein the input laser beams are obtained from very narrow linewidth sources to reduce chromatic dispersion. In some embodiments, diagnostics and adjustments of wavelengths and/or positions and angles are made dynamically in real time to maintain the combination of the plurality input beams into a single high-quality output beam.

Roy D. Mead

Papers

Ultraviolet solid state laser, method of using same and laser surgery apparatus

Use of multiple laser sources for rapid, flexible machining and production of vias in multi-layered substrates

Apparatus and method for spectral-beam combining of high-power fiber lasers

Method and apparatus for spectral-beam combining of fiber-amplified laser beams using high-efficiency dielectric diffractive gratings

Method and apparatus for spectral-beam combining of high-power fiber lasers