Semiconductor laser element and optical data recording device

A semiconductor laser element having a ridge-stripe structure for confining light in a horizontal direction, the element comprising:

• a substrate;
• a first conductivity type lower clad layer formed above the substrate;
• a second conductivity type upper clad layer formed above the lower clad layer, the second conductivity type being different from the first conductivity type;
• and an active layer provided between the lower clad layer and the upper clad layer, the element wherein,
• a refractive index of at least either the lower clad layer or the upper clad layer is below an effective index against light in a basic horizontal-lateral mode, and equal to or more than an effective index against light in a 1st-order horizontal-lateral mode, the light generated in the active layer.

An optical data recording device for recording data in a light recording medium, the data provided in an electrical signal, the device comprising:

• a semiconductor laser element having a ridge-stripe structure for confining light in a horizontal direction;
• recording light radiating control means for allowing radiation of a laser beam for recording from the semiconductor laser element in accordance with the electrical signal;
• light focusing means for focusing a laser beam radiated from the semiconductor laser element;
• and
• irradiating position control means for recording data by irradiating a particular position of a light recording medium with a laser beam collected by the light collecting means, wherein:
• the semiconductor laser element comprises:
• a substrate;
• a first conductivity type lower clad layer formed above the substrate;
• a second conductivity type upper clad layer formed above the lower clad layer, the second conductivity type being different from the first conductivity type;
• and an active layer provided between the lower clad layer and the upper clad layer, the element wherein,
• in at least either the lower clad layer or the upper clad layer, a difference in a radiation loss of light between a basic horizontal-lateral mode and a 1st-order horizontal-lateral mode is 10 cm−1 or more, the light generated in the active layer, the propagation loss of light directed toward a main side of at least either the lower clad layer or the upper clad layer, the main side being opposite to an active layer side of the lower clad layer or the upper clad layer.

An optical data recording device for recording data in a light recording medium, the data provided in an electrical signal, the device comprising:

• a semiconductor laser element having a ridge-stripe structure for confining light in a horizontal direction;
• recording light radiating control means for allowing radiation of a laser beam for recording from the semiconductor laser element in accordance with the electrical signal;
• light focusing means for focusing a laser beam radiated from the semiconductor laser element;
• and
• irradiating position control means for recording data by irradiating a particular position of a light recording medium with a laser beam collected by the light collecting means, wherein:
• the semiconductor laser element comprises:
• a substrate;
• a first conductivity type lower clad layer formed above the substrate;
• a second conductivity type upper clad layer formed above the lower clad layer, the second conductivity type being different from the first conductivity type;
• and an active layer provided between the lower clad layer and the upper clad layer, the element wherein,
• a refractive index of at least either the lower clad layer or the upper clad layer is below an effective index against light in a basic horizontal-lateral mode, and equal to or more than an effective index against light in a 1st-order horizontal-lateral mode, such light generated in the active layer.