Coherent, Inc.

Hoya Corporation

Edward C Rea, Jr

Charles Xiaoyi Wang

Jean-Marc Heritier

Hatim Haloui

Acle V Hicks

An aluminum covered with an anodically formed aluminum oxide layer is marked by repeated bursts of two or more individual laser pulses. The intensity of the individual pulses in the bursts is kept below a level experimentally determined to compromise the integrity of the aluminum oxide layer. The collective fluence in a burst is sufficient to mark the aluminum, but not sufficient to compromise the integrity of the oxide layer.

Method for laser-marking of anodized aluminum

A method for operating an extracavity frequency-converted solid-state laser for performing a laser processing operation is disclosed. The laser has a laser-resonator including an optically-pumped gain-medium. The resonator is configured to compensate for a predetermined range of thermal lensing in the gain-medium. An optically-nonlinear crystal located outside the resonator converts fundamental laser radiation delivered by the resonator into frequency converted radiation. The laser processing operation is performed by a train of pulses of the frequency-converted radiation having sufficient power to perform the processing operation. The power of frequency-converted radiation is dependent on delivery parameters of the laser radiation from the laser-resonator. The laser is operated in a manner which provides that the resonator delivers effectively the same average power of fundamental laser radiation before and during the laser processing operation. This provides that thermal-lensing in the gain-medium is within the predetermined range before and during a laser processing operation. Delivery parameters of the laser radiation before and during the processing operation are varied such that power of frequency-converted radiation generated before the processing operating is insufficient to perform a laser processing operation.

Laser rod thermalization

The use of rectangular cross-section gain material with two or more cylindrical lenses placed in close proximity or attached to opposite sides of the gain material allows for an efficient pumping of the gain material in an optical gain component. The optical gain component can be used in a laser device. Laser diode bars are arranged so as to pump the gain material through the lenses. A cooling apparatus can cool a rectangular cross-section gain material through two opposite flat sides so that no thermal birefringence is created. An optical gain component with two gain materials can orient these two gain materials such that the small-signal gain is almost circular and gaussian in profile with a large center peak tapering off to a much lower gain at the edges.

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Palo Alto, CA, United States of America

Edward C Rea, Jr