Recording head and recorder

A recorder that uses light for information recording on a recording medium, comprising:

• a recording medium;
• a slider which moves relative to the recording medium while not in contact therewith;
• a light source;
• and
• an optical waveguide arranged at a position opposing the recording medium in the slider so as to direct light in a light traveling direction from the light source onto the recording medium, wherein the optical waveguide comprises:
• a cladding;
• and
• a core arranged inside the cladding, wherein the core has a light spot size converter of which an interface with the cladding is formed linearly such that a section perpendicular to the light traveling direction becomes gradually narrow in the light traveling direction from a light input side to a light output side, and
• wherein, when a mode field diameter of the optical waveguide on the light output side is d and mode field diameter of the optical waveguide on the light input side is D, then the relationship D>d is satisfied.

A recording head that uses light for information recording on a recording medium, comprising:

• a slider which moves relative to the recording medium while not in contact therewith;
• a light source;
• and
• an optical waveguide arranged at a position opposing the recording medium in the slider so as to direct light in a light traveling direction from the light source onto the recording medium, wherein the optical waveguide comprises:
• a cladding;
• and
• a core arranged inside the cladding, wherein the core has a light spot size converter of which an interface with the cladding is formed linearly such that a section perpendicular to the light traveling direction becomes gradually narrow in the light traveling direction from a light input side to a light output side, and
• wherein, when a mode field diameter of the optical waveguide on the light output side is d and mode field diameter of the optical waveguide on the light input side is D, then the relationship D>d is satisfied.

A recording head that uses light for information recording on a recording medium, comprising:

• a slider which moves relative to the recording medium while not in contact therewith;
• and
• an optical waveguide arranged at a position opposing the recording medium in the slider so as to direct light in a light traveling direction from a light source onto the recording medium, wherein the optical waveguide comprises:
• a cladding;
• and
• a core arranged inside the cladding, wherein the core has a light spot size converter of which an interface with the cladding is formed linearly such that a section perpendicular to the light traveling direction becomes gradually narrow in the light traveling direction from a light input side to a light output side, and
• wherein, when mode field diameter of the optical waveguide on the light output side is d and mode field diameter of the optical waveguide on the light input side is D, then D>d is fulfilled.