Nec Corporation

Konoshima Chemical Co., Ltd.

Laserfront Technologies, Inc.

Masaki Tsunekane

Katsuji Mukaihara

Shuetsu Kudo

Hideki Yagi

Yoshikazu Suzuki

Hikaru Kouta

Takagimi Yanagitani

Hideyuki Moribe

Takashi Ooyama

As a composite laser rod capable of satisfying the positional stability and output stability of a laser beam, a laser rod in which a laser active element is doped is intimately inserted into a hollow portion of a non-doped ceramic pipe that has a crystal structure the same as the laser rod followed by baking so as to remove a gap and strain at an interface between the laser rod and the ceramic pipe after the baking further followed by polishing a surface of the ceramic pipe to form a ceramic skin layer, and thereby a composite laser rod is formed. In the composite laser rod, an influence due to fluctuation in the cooling capacity of cooling water or a heat sink is averaged by a non-doped skin layer, temperature fluctuation of the laser rod is suppressed, and an influence of vibration from the cooling water or a cooling fan can be suppressed. When the refractive index of the laser rod is made higher than that of the ceramic pipe, a high efficiency oscillation can be realized, and furthermore when the thermal conductivity of the ceramic pipe is made higher than that of the laser rod, the thermal lens effect can be alleviated.

Composite laser rod, fabricating method thereof, and laser device therewith

A conventional method for a solid-state laser device that obtains a laser beam output of a high quality at a high output using a laser diode as a pumping light source has a problem that the costs are increased and the fabrication becomes complicated due to an increasing number of components, such as a diffusing reflection mirror, a condenser lens, and a holding mechanism and a cooling mechanism thereof. Coating with a antireflection coating to reduce a transmission loss of laser diode light, and coating with a high reflection coating to reflect the laser diode light are provided alternately on the outer surface of a cooling tube. Also, an irradiation direction of the laser diode is not directed to the center of the laser rod, but is given with a certain angle to be positively tilted. This configuration makes it possible to eliminate the above problem.

Diode-pumped solid-state laser device and manufacturing method of the same

A semiconductor laser device in a semiconductor-laser excited solid-state laser apparatus is provided with a plurality of semiconductor laser diodes connected in series to one another. Each of a plurality of bypass diodes is connected in parallel to each semiconductor laser diode or each group of at least two semiconductor laser diodes in the plurality of semiconductor laser diodes and has a higher rising voltage than a rising voltage of the parallel-connected semiconductor laser diodes. The polarity of one end of each of the semiconductors laser diode is the same as the polarity of that end of the associated bypass diode which is connected to the one end of that semiconductor laser diode and the polarity of the other end of the semiconductor laser diode is the same as the polarity of that end of the associated bypass diode which is connected to the other end of that semiconductor laser diode. This structure accomplish continuous light emission with a simple and compactable circuit structure even if one or more semiconductor laser diodes are disconnected, thereby making the semiconductor laser device highly reliable.

Semiconductor laser device and semiconductor-laser excited solid-state laser apparatus

A laser-diode-pumped solid-state laser apparatus includes a laser rod, and laser diode devices that generate pumping light. Optical unit such as a reflection mirror and an optical waveguide medium is provided at a position in a laser resonator near a laser optical axis and not blocking the optical axis. A photo-detector detects a quantity of fluorescence generated from solid-state laser medium. The fluorescence quantity is compared with a predetermined value or a previously measured value. Thus degradation status of a laser diode light source is constantly diagnosed.

Laser-diode-pumped solid-state laser apparatus and status diagnostic method of the same

A diode-laser side-pumped solid-state laser device (SSLD) has a cylindrical laser rod, a cooling tube, and a cylindrical mirror member having an inner mirror surface and a plurality of openings therein for introducing pumping laser. The laser rod receives the pumping laser, absorbs a portion of the pumping laser, and passes and focus the remaining portion of the pumping laser at a focal point disposed on the mirror surface. Substantially all the remaining portion of the pumping laser is reflected to be received and absorbed by the laser rod.

Growing community of inventors

Tokyo, Japan

Masaki Tsunekane