Abstract: A laser light beam of a first wavelength which is polarized in a first polarizing direction, emitted from first and second semiconductor laser elements and reflected by an information recording surface of an optical recording medium, is made to be transmitted by a second polarizing hologram diffraction grating and diffracted in a direction toward a light receiving element by a first polarizing hologram diffraction grating. A laser light beam of a second wavelength which is polarized in the first polarizing direction, reflected by the information recording surface of the optical recording medium, is made to be converted so to be in a second polarizing direction by the 5?/4 plate. A laser light beam of the second wavelength which is polarized in the second polarizing direction is made to be diffracted in the direction toward the light emitting element by the second polarizing hologram diffraction grating.

Abstract: A semiconductor laser device has a semiconductor laser element, a starting mirror and a signal photodetector mounted on a surface of laminate ceramic package which is formed by layering a plurality of ceramic sheets having mutually different conductive patterns. The semiconductor laser device and an optical pickup apparatus having the device allow to eliminate the restrictions on arrangement of wire-bonded electrodes and wiring layout and to reduce the adverse effect of heat generated in the photodetector on the semiconductor laser element.

Abstract: A laser light beam of a first wavelength which is polarized in a first polarizing direction, emitted from first and second semiconductor laser elements and reflected by an information recording surface of an optical recording medium, is made to be transmitted by a second polarizing hologram diffraction grating and diffracted in a direction toward a light receiving element by a first polarizing hologram diffraction grating. A laser light beam of a second wavelength which is polarized in the first polarizing direction, reflected by the information recording surface of the optical recording medium, is made to be converted so to be in a second polarizing direction by the 5?/4 plate. A laser light beam of the second wavelength which is polarized in the second polarizing direction is made to be diffracted in the direction toward the light emitting element by the second polarizing hologram diffraction grating.

Abstract: After a birefringent layer having a diffraction surface is formed on a light transmitting substrate and an isotropic overcoat layer is formed on the diffraction surface of the birefringent layer, the light transmitting substrate is formed on the isotropic overcoat layer, whereby first and second polarizing hologram substrates are formed. Between respective surfaces of the first and second polarizing hologram substrates facing each other, a light transmitting adhesive is applied uniformly, and the first polarizing hologram substrate and the second polarizing hologram substrate are adhered. Thus, a hologram coupled member in which an optical coupling layer formed as a result of cure of the light transmitting adhesive is interposed is formed between the mutually facing surfaces of the first and second polarizing hologram substrates.