Semiconductor laser array and its manufacturing method, optical integrated unit and optical pickup

An optical pickup comprising:

• an optical integrated unit including an integrated laser array and a detector, said integrated laser array including a first laser element portion and a second laser element portion integrated side by side on a common substrate, said first laser element portion releasing laser light of a first wavelength, said second laser element portion releasing laser light of a second wavelength different from said first wavelength in a direction substantially parallel to the laser light of said first wavelength, said detector detecting first reflected return light which is part of the laser light of said first wavelength and second reflected return light which is part of the laser light of said second wavelength, said detector being placed sideward of the integrated laser array so that a plane which includes axes of the laser lights released from the first and second laser element portions intersects the detector;
• and
• a holographic optical element to diffract said first return light by a first diffraction angle and said second return light by a second diffraction angle different from said first diffraction angle;
• wherein the holographic optical element diffracts the first and second reflected return lights onto a common location within the detector.

An optical pickup comprising:

• an optical integrated unit including an integrated laser array and a detector, said integrated laser array including a first laser element portion and a second laser element portion integrated side by side on a common substrate, said first laser element portion releasing laser light of a first wavelength, said second laser element portion releasing laser light of a second wavelength different from said first wavelength in a direction substantially parallel to the laser light of said first wavelength, said detector detecting first reflected return light which is part of the laser light of said first wavelength and second reflected return light which is part of the laser light of said second wavelength, said detector being placed sideward of the integrated laser array so that a plane which includes axes of the laser lights released from the first and second laser element portions intersects the detector;
• and
• an optical system configured to receive said laser light of a first wavelength and said laser light of a second wavelength and direct it onto an optical disk, and to guide light reflected back from said optical disk to said optical integrated unit;
• wherein the detector is configured to receive and detect the first reflected return light and the second reflected return light at a common location within the detector.

An optical integrated unit comprising:

• an integrated laser array including a first laser element portion and a second laser element portion integrated side by side on a common substrate, said first laser element portion releasing laser light of a first wavelength, and said second laser element portion releasing light of a second wavelength different from said first wavelength in a direction substantially parallel to the laser light of said first wavelength;
• and
• a detector configured to detect first reflected return light which is part of the laser light of said first wavelength and second reflected return light which is part of the laser light of said second wavelength;
• wherein the detector is configured to receive and detect the first reflected return light and the second reflected return light at a common location within the detector.