Light source unit, thermally assisted magnetic head, head gimbal assembly, and hard disk drive

A light source unit, wherein

• the light source unit is applicable for a thermally assisted magnetic head, the thermally assisted magnetic head comprises a slider, and the slider is provided with a waveguide and with a first cavity for accommodating the light source unit;
• a welding layer and a stopping structure are provided between the light source unit and the slider;
• and
• wherein the light source unit is configured to move as the welding layer melts and be limited at a preset position by the stopping structure, when joined with the slider, and at the preset position, an emission opening of the light source unit aligns with the waveguide,
• wherein the slider comprises a slider body and a conductive layer, wherein the conductive layer is connected to the slider body and the conductive layer is provided for connecting with the welding layer;
• the light source unit comprises a light source body and a first electrical connecting layer, the first electrical connecting layer is connected with the light source body, and the welding layer is configured to be provided on the first electrical connecting layer or the conductive layer.