Near field light generating device and heat assisted magnetic recording head with the same

A heat assisted magnetic recording head, comprising:

• a recording pole which generates magnetic flux leakage for magnetic recording on a recording medium;
• and
• a near field light generating device, adjacent to the recording pole, which irradiates light onto the recording medium prior to the magnetic flux leakage,
• wherein the near field light generating device comprises:
• a light source
• a waveguide core which transmits light emitted form the light source;
• and
• a solid immersion mirror which generates near field light, comprising:
• an upper transmission surface through which light from the waveguide core is transmitted into the solid immersion mirror;
• a lower reflection surface, opposite the upper transmission surface, which reflects light incident thereon;
• lateral reflection surfaces, facing each other at sides of the solid immersion mirror, which reflect light incident thereon;
• and
• a lower transmission region disposed at a center of the lower reflection surface;
• wherein light reflected from the lateral reflection surfaces forms a light spot on the lower transmission region,
• wherein the waveguide core is a flat panel type;
• wherein the solid immersion mirror is a flat panel type;
• wherein the effective refractive index of the solid immersion mirror is greater than the effective refractive index of the wave guide core;
• and
• wherein the thickness of the solid immersion mirror is greater than the thickness of the waveguide core.