Patent ID: 8270791
Filing Date: 2012-09-18
Classification: B82Y,G02B,G11B

Abstract:
1. A waveguide for a thermally-assisted magnetic head, comprising: a first section having a first width, the first section including a grating formed with a predetermined number of concave grooves along a light propagation direction of the waveguide, each concave groove extending in a width direction; a second section having a second width, the second width being less than the first width; a third section positioned between the first and second sections and having a third width that gradually changes from the first width to the second width in the light propagation direction, the first, second and third sections having substantially the same thickness; and a transverse electric-transverse magnetic (TE-TM) mode conversion element in the second section, wherein laser light is incident perpendicularly onto the first section and propagates in the light propagation direction to the second section through the third section, the concave grooves of the grating are provided at a predetermined pitch that is smaller than a wavelength of the perpendicularly incident laser light, the second width of the second section is configured to produce evanescent light based on the laser light that has propagated and advanced to the second section, and a groove depth H