Corelase Oy

Coherent, Inc.

Rofin-sinar Laser Gmbh

Oy Nokia Ab

Vg Systems Limited

Arto K Salokatve

Jarno Kangastupa

Jari Näppi

Tuomo Konnunaho

Harry Asonen

Tiina Amberla

Kalle Ylä-Jarkko

Markus Pessa

Jari Tapani Naeppi

Juan L A Chilla

David C Poole

Jukka Varrio

The invention concerns an apparatus and its use for laser welding. A laser welding apparatus comprise at least one first laser device, each providing at least one first optical feed fiber with a first laser beam; at least one second laser device, each providing at least one second optical feed fiber with a second laser beam; means for generating a composite laser beam comprising a first output laser beam and a second output laser beam for welding a workpiece; wherein the first output laser beam has a circular cross-section and the second output laser beam has an annular shape concentric to the first output laser beam. The second laser device is a fiber laser device or a fiber-coupled laser device. The apparatus is configured to form the second output laser beam at least on the basis of the second laser beam, and the second output laser beam comprises a first wavelength and a second wavelength having difference of at least 10 nanometers, or the second output laser beam has spectrum width of least 10 nanometers.

Laser processing apparatus and method

An apparatus and its use for laser processing along with a method and an optical component. A first laser device provides a first optical feed fiber and a second laser device provides a second optical feed fiber. A beam combining means connected to the first and second feed fibers and to a multi-core optical fiber is adapted to form a composite laser beam by having the first optical feed fiber aligned with a first core of the multi-core optical fiber and the second optical feed fiber aligned with at least one second core of the multi-core optical fiber. The first and second cores outputs a composite laser beam to a workpiece to be processed. A control unit individually controls the power density of the output laser beams.

Laser processing apparatus and method and an optical component therefor

A pump reflector for efficiently recycling unabsorbed pump radiation in a diode-pumped fiber laser includes a core for guiding a laser beam, a pump cladding, and a tapered capillary tube. Pump radiation is adiabatically guided in the tapered capillary tube, which includes a mirror that is reflective for the pump radiation. The pump reflector may be packaged as a fiber component for co-propagating or counter-propagating fiber laser amplifiers and resonators.

Fiber laser pump reflector

The present invention provides a packaging for a fiber optic component, such as an optical fiber, wherein the heating induced strain to the fiber optic component is minimized, wherein the packaging comprises a first support member having a first coefficient of thermal expansion (k). The packaging further comprises a second support member, which is resiliently mounted to the first support member for minimizing transfer of thermal expansion induced strain of the first support member to the second support member. The second support member comprises a longitudinal groove open at least on one side of the second support member for receiving a fiber optic component, wherein the second support member has a tensile strength considerably higher than that of the fiber optic component. The second support member has a second coefficient of thermal expansion (k) substantially smaller than the first coefficient of thermal expansion (k), wherein the first support member is adapted to exchange heat induced by free-space radiation. The second support member is made of material, such as quartz, which is transparent to the wavelengths used in the component.

Packaging for a fiber optic component and manufacturing method thereof

The invention concerns a fiber-optic component, in particular a fiber coupler, and method for manufacturing thereof. The component comprises a housing (), at least one first optical element () capable of guiding light and having an output end, the first optical element () being affixed to said housing () at a mounting zone (A), and at least one second optical element () optically coupled to the first optical element () at a coupling zone () for receiving light from the output end of the first optical element (). According to the invention, the component comprises at least one zone () of light-scattering material arranged in the vicinity of the first optical element () at a region between the coupling zone () and the mounting zone (A). By means of the invention, the effect potentially harmful reverse radiation in fiber-optic components can be mitigated.

Packaged fiber-optic component and method of manufacturing thereof

A fiber optic mode scrambler includes a multi-mode optical fiber formed with a core and a cladding around the core and a non-adiabatic cross-sectional shape change zone in the optical fiber. The fiber further has a bending region extending over a length of the optical fiber. The optical fiber has a non-zero curvature at the bending region and a device for maintaining the curvature of the optical fiber at the bending region. Mode scramblers can be provided that are accurately adjusted to match with different desired optical characteristics. A well-controlled manufacturing method for the mode scrambler is also described.

Fiber optic mode scrambler and a method of manufacturing thereof

The invention relates to a pump coupler () and a manufacturing method. The pump coupler () comprises a least one signal fiber () for outputting optical energy, multiple pump fibers () for inputting optical energy into the signal fiber (), and a coupling structure () for coupling the optical energy of the pump fibers () into the signal fiber (). A signal feed-through fiber () goes through the coupling structure (). In accordance with the invention the coupling structure () is a tapering capillary tube () having a first wide end () and a second narrow end (), the pump fibers () are connected to the wide end of the capillary tube (), and at least the narrow end () of the capillary tube () is collapsed around the signal fiber ().

Means of coupling light into optical fibers and methods of manufacturing a coupler

An active multimode optical fiber consisting of a first core section (), a thin barrier layer () material having a thickness (d) and a lower refractive index than that of the first core section by an index difference (&#x394;n), a second core section () having a refractive index equal or higher than that of the first core section, and a cladding () having an index lower than that of the first core section. Said index difference and said thickness are selected so that a fundamental core mode couples less strongly with said cladding modes than higher order core modes. A scheme of changing the symmetry of the fiber for reduced sensitivity of the fundamental mode of the first core section to resonance effects.

Optical fiber gain medium with modal discrimination of amplification

A printer head for computer-to-plate printing includes a linear array of individually addressable diode-lasers and a linear array of photodetectors. The number and spacing of the photodetectors is the same as the number and spacing of the diode-lasers. The diode-lasers emit in forward and reverse directions. The diode-lasers and photodetectors are aligned parallel to each other such that reverse-emitted light output of each diode-laser is incident on a corresponding photodetector. Each photodetector output is monitored by a dedicated controller/driver sub-circuit that regulates drive current supplied to the diode-laser. The drive current is regulated according to a comparison of the monitored photodetector output with a reference current individually calibrated in each sub-circuit. Calibration data for each sub-circuit is obtained from a measurement of forward-emitted output power of its corresponding diode-laser compared with a desired target forward-emitted power. The individual calibration of the sub-circuits provides that each of the diode-lasers emits at the target output power.

Printer head with linear array of individually addressable diode-lasers

A optically-pumped semiconductor (OPS), vertical-cavity, surface-emitting laser (VCSEL) includes a first mirror having a quantum-well structure thereon which provides a gain medium for the laser. A second mirror is spaced apart from the quantum-well structure and, together with the first mirror, forms a resonant cavity for the laser. Optical pump-radiation is directed through the gap into the quantum-well structure via an outermost layer of the quantum-well structure. The quantum-well structure includes a plurality of quantum-well layers spaced apart by pump-radiation absorbing layers. Quantum-well and pump-radiation absorbing layers are aluminum-free layers of alloys of the GaAs/InGaAsP system.

Optically-pumped external-mirror vertical-cavity semiconductor-laser

An effusion cell (22) including a crucible (28) is configured such that when attached to the MBE apparatus at a predetermined distance from a rotatable substrate holder (24), a longitudinal axis (32) of the crucible is directed toward the substrate holder at an angle to the rotation axis (26) of the substrate holder. The crucible is heatable for melting a material (36) placed therein, the molten material forming a melt surface (38) from which molecules of the material are evaporated. The top of the crucible has an elliptical opening (31), the plane of which is parallel to the substrate holder. The crucible and the opening therein are configured such that a substrate (25) in the substrate holder receives only evaporated molecules which proceed directly thereto from the melt surface, through the opening. The evaporated molecules received by the substrate are contributed from an area of the melt surface which increases in proportion to the square of the distance of the melt surface from the substrate holder, as that distance increases due to depletion of the material in the crucible by evaporation. This provides that molecular flux on the substrate remains constant during the depletion.

Effusion cell and method of use in molecular beam epitaxy

The invention relates to a method of growing a GaAs film on the surface of a Si or GaAs substrate by exposing the growing surface of the substrate in a vacuum to at least one vapor beam containing the Ga elementary component of the GaAs compound, and to at least one vapor beam containing the As elementary component of the GaAs compound. The method is characterized by the steps of (A) growing a GaAs buffer layer by alternately applying the elements of the GaAs compound to the surface of a substrate heated to a first temperature one atom layer at a time, whereby in the formation of each atom layer the growing surface is exposed to a vapour beam containing one elementary component of the GaAs compound only; and (B) heating the substrate to a second temperature higher than the first temperature, and growing another GaAs layer on the buffer layer by applying both of the elementary components of the GaAs compound simultaneously.

Growing community of inventors

Tampere, Finland

Arto K Salokatve