Hitachi, Ltd.

Misuzu Yoshizawa

Kazuhisa Uomi

Takashi Kajimura

Yuichi Ono

Naoki Chinone

Toshihiro Kawano

Shin'ichi Nakatsuka

A phased array semiconductor laser has two or more luminous stripes. The number, width or center to center spacing of stripes is made different between the center region and neighborhood of facets of the laser so that the laser may oscillate stably in the fundamental supermode with an optical output of 100 mW or more.

Semiconductor laser

Disclosed is a semiconductor laser wherein an interface layer is provided on an upper cladding layer formed on an active layer, the interface layer having a smaller Al mole ratio than that of the upper cladding layer, thereby preventing oxidation of the semiconductor surface which is exposed to the atmosphere, and thus improving the crystallizability of a semiconductor layer which is to be formed subsequently. By setting the refractive index of this semiconductor layer so as to be smaller than that of the upper cladding layer, light can be confined in the active layer at increased efficiency.

Semiconductor laser device having high optical intensity and reliability

The present invention relates to phased-array semiconductor lasers having a radiation angle turnable by oscillating independently and stably between the fundamental supermode and the higher order supermode and switching the radiation angles by utilizing the property that their radiation angles are different. Optical switching and optical scanning, that have been difficult in the prior art, can be made more easily by use of a semiconductor laser having a turnable radiation angle. The objection of the present invention can be accomplished by disposing separate electrodes at the emission stripes and at the gap between the stripes in the phased-array semiconductor laser. Further, the present invention may be accomplished by dividing at least one stripe electrode in order to form electrode regions. When the current is applied to all the electrodes, oscillation occurs in the highest order mode and the beam is emitted in another direction. When the current is applied to only the electrode exclusive of the electrode regions, oscillation occurs in the fundamental mode and the beam is emitted in a direction vertical to a facet. Moreover, the present invention may be accomplished by disposing electrodes outside the stripe regions of the phased-array semiconductor laser so that oscillation occurs in the fundamental supermode when the electric field is applied to the electrodes and in the higher order mode when the electric field is not applied.

Growing community of inventors

Tokyo, Japan

Misuzu Yoshizawa