JP2010123226A - Near field light head and information recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a near field light head which can efficiently generate near field light from introduced luminous flux, and to provide an information recording and reproducing device. <P>SOLUTION: The near field light head 2, which heats a magnetic recording medium D by near field light R and records information in the magnetic recording medium, includes: a slider 20 arranged opposing to the surface D1 of the magnetic recording medium; a near field light generation element 22 generating near field light using luminous flux L; and a luminous flux introduction means 4 for introducing luminous flux to the near field light generation element. The near field light generation element is formed of a material transmitting luminous flux, and includes: a core 40 having a reflection plane 40a reflecting luminous flux introduced from the luminous flux introduction means to the magnetic recording medium side; and a clad 41 covering a core formed with a material of which the refractive index is lower than the core. The optical axis of the luminous flux introduction means is tilted for the surface 20a opposing to the magnetic recording medium in the slider so that a whole light in a spot diameter out of luminous flux introduced from the luminous introduction means is reflected by the reflecting plane. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention condenses various information on a magnetic recording medium using a near-field light generated by a near-field light generating element that condenses the introduced light flux and generates near-field light from the light flux. The present invention relates to a near-field optical head for recording and an information recording / reproducing apparatus having the near-field optical head.

  In recent years, the recording density of information within a single recording surface has increased as the capacity of hard disks and the like in computer equipment has increased. For example, in order to increase the recording capacity per unit area of the magnetic disk, it is necessary to increase the surface recording density. However, as the recording density increases, the recording area occupied by one bit on the recording medium decreases. When this bit size is reduced, the energy of 1-bit information becomes close to the thermal energy at room temperature, and the recorded information is reversed or disappears due to thermal fluctuations, etc. Will occur.

  In the in-plane recording method that has been generally used, the magnetism is recorded so that the direction of magnetization is in the in-plane direction of the recording medium. In this method, the recorded information is lost due to the thermal demagnetization described above. Is likely to occur. Therefore, in order to solve such a problem, a shift is being made to a perpendicular recording method in which a magnetization signal is recorded in a direction perpendicular to the recording medium. This method is a method for recording magnetic information on the principle of bringing a single magnetic pole closer to a recording medium. According to this method, the recording magnetic field is directed substantially perpendicular to the recording film. Information recorded by a perpendicular magnetic field is easy to maintain in energy stability because it is difficult for the N pole and the S pole to form a loop in the recording film surface. Therefore, this perpendicular recording method is more resistant to thermal demagnetization than the in-plane recording method.

  However, recent recording media are required to have a higher density in response to the need to record and reproduce a larger amount and higher density information. For this reason, in order to minimize the influence of adjacent magnetic domains and thermal fluctuations, those having a strong coercive force have begun to be adopted as recording media. For this reason, it is difficult to record information on a recording medium even in the above-described perpendicular recording system.

In order to solve such problems, there is a hybrid magnetic recording method (near-field light assisted magnetic recording method) in which the magnetic domain is locally heated by near-field light to temporarily reduce the coercive force, and writing is performed during that time. Proposed. This hybrid magnetic recording system is a system that uses near-field light generated by the interaction between a minute region and an optical aperture formed in a size equal to or smaller than the wavelength of light formed in the near-field optical head. In this way, by using a small optical aperture exceeding the light diffraction limit, that is, a near-field light head having a near-field light generating element, it is less than the wavelength of light that has been regarded as a limit in conventional optical systems. It is possible to handle the optical information in the region. Therefore, it is possible to increase the recording bit density exceeding that of the conventional optical information recording / reproducing apparatus.
Note that the near-field light generating element is not limited to the above-described optical micro-aperture, and may be constituted by, for example, a protrusion formed in a nanometer size. This projection can also generate near-field light in the same manner as the optical minute aperture.

  Various types of recording heads have been proposed as the above-described hybrid magnetic recording system, and one of them is a near-field optical head in which the recording density is increased by reducing the size of the light spot. (For example, refer to Patent Document 1).

  As shown in FIG. 15, this near-field optical head 102 was irradiated with a slider 120, a main magnetic pole 132, an auxiliary magnetic pole 130, and a coil 133 in which a spiral conductor pattern was formed inside an insulator. A near-field light generating element 122 that generates near-field light from laser light, a laser light source (not shown) that irradiates the near-field light generating element with laser light, and a light beam L emitted from the laser light source is converted into near-field light. And an optical waveguide 104 that leads to the generating element.

  One end of the main magnetic pole 132 is a surface facing the recording medium D, and the other end is connected to the auxiliary magnetic pole 130. That is, the main magnetic pole 132 and the auxiliary magnetic pole 130 constitute a single magnetic pole type vertical head in which one magnetic pole (single magnetic pole) is arranged in the vertical direction. Further, the coil 133 is disposed so that a part of the coil 133 passes between the main magnetic pole 132 and the auxiliary magnetic pole 130. The main magnetic pole 132, the auxiliary magnetic pole 130, and the coil 133 constitute an electromagnet as a whole.

When the near-field light head 102 configured as described above is used, various information is recorded on the recording medium D by generating the near-field light R and simultaneously applying a recording magnetic field.
That is, the laser light emitted from the laser light source is guided to the near-field light generating element 122 via the optical waveguide 104. Then, since free electrons inside the core 140 of the near-field light generating element 122 are uniformly vibrated by the electric field of the laser light, plasmons are excited to generate near-field light R at the tip portion. As a result, the magnetic recording layer of the recording medium D is locally heated by the near-field light R, and the coercive force temporarily decreases.
Simultaneously with the irradiation of the laser beam, a recording magnetic field is locally applied to the magnetic recording layer of the recording medium D adjacent to the main magnetic pole 132 by supplying a drive current to the coil 133. Thereby, various types of information can be recorded on the magnetic recording layer whose coercive force has temporarily decreased. That is, recording on the recording medium D can be performed by the cooperation of the near-field light R and the magnetic field.
JP 2008-152897 A

However, in the conventional near-field light head described above, the direction in which the optical waveguide 104 is orthogonal to the surface of the near-field light generating element 122 that receives the light beam L (the optical waveguide 104 and the facing surface 120a facing the surface of the disk D). Are connected in parallel). When the light flux L (light within the spot diameter) enters the near-field light generating element 122 from such a direction, all the light flux L is not reflected on the reflecting surface 140a, and light leakage occurs.
Specifically, when the optical waveguide 104 is connected to the near-field light generating element 122 in a state parallel to the upper surface of the slider 120, the light beam L is incident on the core 140 as shown in FIG. Reflected at 140a. Here, since the light beam L is incident on the reflecting surface 140a radially, the incident angle θ8 of the light beam L is not constant. Therefore, a part of the light beam L is transmitted without being totally reflected on the reflecting surface 140a, and light loss occurs. When the incident angle θ8 is less than 41 ° with respect to the reflecting surface 140a, the incident light is not totally reflected and a part of the light is transmitted through the core 140, resulting in light loss. That is, since the light transmitted through the core 140 (refracted transmission light component) is not generated as the near-field light R, there is a problem that the near-field light R cannot be generated efficiently.
Further, it is conceivable to adjust the inclination angle of the reflecting surface 140a so that the angle (incident angle θ8) formed by the light beam L and the reflecting surface 140a is larger than a predetermined angle. Therefore, it is difficult to independently adjust the inclination angle of the reflecting surface 140a.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a near-field optical head and an information recording / reproducing apparatus capable of efficiently generating near-field light from an introduced light beam. .

The present invention provides the following means in order to solve the above problems.
The near-field optical head according to the present invention heats a magnetic recording medium rotating in a certain direction with near-field light and causes a magnetization reversal by applying a recording magnetic field to the magnetic recording medium to record information. A near-field optical head, comprising a slider opposed to the surface of the magnetic recording medium, a support member that supports the slider, and a light beam that is attached to the slider and introduced from the support member side. A near-field light generating element that generates the near-field light on the magnetic recording medium side; and a light-flux introducing unit that introduces a light beam to the support member side of the near-field light generating element. A core formed of a material that transmits the light beam and having a reflecting surface that reflects the light beam introduced from the light beam introducing unit toward the magnetic recording medium, and a material having a refractive index lower than that of the core The magnetic recording medium in the slider so that all of the light within the spot diameter of the light beam introduced from the light beam introducing means is reflected on the reflecting surface. The optical axis of the light beam introducing means is inclined with respect to the surface facing the surface.

  In the near-field light head according to the present invention, the near-field light generating element has a core having a reflective surface and a clad that confines the core inside, and the light flux introduced into the core is reflected in the near-field light. Can be emitted to the outside. The clad is formed so as to be in close contact with the side surface of the core by a material having a refractive index lower than that of the core, and confines the core so that no gap is formed between the clad and the core. Here, when a light beam is introduced into the core, the light beam is reflected by the reflecting surface and changes its direction. That is, the direction changes in a direction different from the introduction direction. Then, the luminous flux whose direction has changed propagates inside the core toward the magnetic recording medium side.

  The light beam propagates through the core while being repeatedly reflected in the core. In particular, since the cladding is in close contact with the side surface of the core, light does not leak to the outside of the core, and the introduced light beam can be propagated to the magnetic recording medium side without wasting it.

As described above, the light beam introduced from the core support member side can be converted into near-field light, and the near-field light can be emitted to the outside from the magnetic recording medium side. That is, it is possible to efficiently generate near-field light from the light flux by focusing while changing the direction of the introduced light flux.
The light beam here means a light beam within the spot diameter of the light emitted from the light beam introducing means. The spot diameter generally means within a range of 1 / e ² (about 13.5%, e is the base of natural logarithm) of the central light intensity.

  Further, the light flux introducing means is arranged so that the optical axis of the light flux introducing means is inclined with respect to the surface of the slider facing the magnetic recording medium, and the light flux introduced from the light flux introducing means to the near-field light generating element is reflected on the reflecting surface. Since all are reflected, near field light can be generated efficiently.

  Specifically, the light beam entering the near-field light generating element (reflecting surface) by arranging the light beam introducing unit so that the optical axis of the light beam introducing unit is inclined with respect to the surface of the slider facing the magnetic recording medium. The incident angle changes. The angle formed between the light beam introducing means and the surface of the slider facing the magnetic recording medium is adjusted so that all the light within the spot diameter of the light beam is totally reflected on the reflecting surface. Furthermore, if the incident angle becomes too large, the light is totally reflected on the reflecting surface, but when it propagates into the core after that, the incident angle of the reflected light with respect to the side surface in the core becomes small, and the inside of the core is reduced. Light loss occurs in Therefore, the angle formed between the light beam introducing means and the surface of the slider facing the magnetic recording medium is adjusted to a predetermined angle, and all the light beams introduced from the light beam introducing means to the near-field light generating element are reflected by the reflecting surface. In addition, by configuring the reflected light to be guided to the end portion that generates near-field light, no optical loss occurs, and near-field light can be generated with high efficiency.

  In addition, since the near-field light generating element capable of efficiently generating near-field light is provided, the writing reliability of the near-field light head itself can be improved, and high quality can be achieved. Further, since the light beam is introduced into the near-field light generating element via the light beam introducing means, the light guide loss can be reduced as much as possible compared with the case where the light beam is propagated in the air and introduced.

  In the near-field light head according to the present invention, the near-field light generating element may be configured such that a cross-sectional area of the core perpendicular to the optical axis gradually decreases from the support member side toward the magnetic recording medium side. A formed light flux condensing unit; and a near-field light generating unit that generates the near-field light from the collected light flux, and the reflecting surface receives the light flux introduced from the light flux introducing means. All of the light within the spot diameter is reflected by the reflecting surface, and all of the reflected light is reflected by the light flux collecting portion. The optical axis of the light flux introducing means is inclined with respect to the surface of the slider facing the magnetic recording medium so that it is propagated through the optical part and guided to the near-field light generating part. Yes.

  In the near-field light head according to the present invention, a polyhedral core in which the near-field light generating element is integrally formed by the reflecting surface, the light beam condensing unit, and the near-field light generating unit, and a clad for confining the core inside The luminous flux introduced into the core can be emitted to the outside as near-field light. The clad is formed so as to be in close contact with the side surface of the core by a material having a refractive index lower than that of the core, and confines the core so that no gap is formed between the clad and the core. Here, when a light beam is introduced into the core, the light beam is reflected by the reflecting surface and changes its direction. That is, the direction changes in a direction different from the introduction direction. Then, the light flux whose direction has changed is propagated in the core from the support member side to the magnetic recording medium side by the light flux condensing part.

  In addition, the light beam condensing part is formed by drawing so that the cross-sectional area perpendicular to the longitudinal direction from the support member side toward the magnetic recording medium side gradually decreases. Therefore, when the light beam passes through the light beam condensing part, it is gradually condensed while repeating reflection on the side surface and propagates through the core. In particular, since the clad is in close contact with the side surface of the core, light does not leak to the outside of the core, and the introduced light beam can be propagated to the magnetic recording medium side without being wasted.

  As described above, the light beam introduced from the core support member side can be converted into near-field light, and the near-field light can be emitted to the outside from the magnetic recording medium side. That is, it is possible to efficiently generate near-field light from the light flux by focusing while changing the direction of the introduced light flux.

  Further, the angle formed between the light beam introducing means and the surface of the slider facing the magnetic recording medium is adjusted to a predetermined angle, and all the light beams introduced from the light beam introducing means to the near-field light generating element are reflected on the reflecting surface, And since it was comprised so that the reflected light might be guide | induced to a near-field light production | generation part, a near-field light can be generated efficiently.

  Specifically, the incident angle of the light beam incident on the near-field light generating element (reflection surface) is changed by adjusting the angle formed between the light beam introducing means and the surface of the slider facing the magnetic recording medium. The angle formed between the light beam introducing means and the surface of the slider facing the magnetic recording medium is adjusted so that all the light within the spot diameter of the light beam is totally reflected on the reflecting surface. Furthermore, if the incident angle becomes too large, the light is totally reflected on the reflecting surface, but when the light is subsequently propagated to the light beam condensing unit, the incident angle of the reflected light with respect to the side surface of the light beam condensing unit becomes small. As a result, light loss occurs in the light beam condensing part. Therefore, the angle formed between the light beam introducing means and the surface of the slider facing the magnetic recording medium is adjusted to a predetermined angle, and all the light beams introduced from the light beam introducing means to the near-field light generating element are reflected by the reflecting surface. In addition, by configuring the reflected light to be guided to the near-field light generation unit, no optical loss occurs, and near-field light can be generated with high efficiency.

  In addition, since the near-field light generating element capable of efficiently generating near-field light is provided, the writing reliability of the near-field light head itself can be improved, and high quality can be achieved. Further, since the light beam is introduced into the near-field light generating element via the light beam introducing means, the light guide loss can be reduced as much as possible compared with the case where the light beam is propagated in the air and introduced.

  In the near-field light head according to the present invention, the vicinity of the tip connected to the near-field light generating element in the light flux introducing means is accommodated in a structure that can be placed on the upper surface of the slider. The light flux introducing means and the core are connected at the predetermined angle in a state where the light flux introducing means is held so as to be inclined with respect to a surface of the slider facing the magnetic recording medium. .

  In the near-field light head according to the present invention, the arrangement angle of the light beam introducing means can be fixed with respect to the core of the near-field light generating element. Therefore, by forming the arrangement angle of the light flux introducing means so that the angle formed between the light flux introducing means and the surface of the slider facing the magnetic recording medium is a predetermined angle, All of the light flux introduced into the core of the light generating element is reflected by the reflecting surface, and the reflected light can be guided to the near-field light generating unit. That is, near-field light can be generated efficiently.

  An information recording / reproducing apparatus according to the present invention is configured to be movable in a direction parallel to the surface of the magnetic recording medium, and the near-field optical head according to any one of the present inventions described above. A rotating member that is supported on the front end side, a light source that causes the light beam to enter the light beam introducing means, a base end side of the rotating member, and a rotating member that is attached to the surface of the magnetic recording medium An actuator for moving in a parallel direction, a rotation driving unit for rotating the magnetic recording medium in the fixed direction, and a control unit for controlling the operation of the light source are provided.

  Since the information recording / reproducing apparatus according to the present invention includes the near-field optical head described above, writing reliability is high, high-density recording can be achieved, and high quality can be achieved.

  According to the near-field light head of the present invention, the angle formed between the light flux introducing means and the surface of the slider facing the magnetic recording medium is adjusted to a predetermined angle and introduced from the light flux introducing means to the near-field light generating element. Since all the reflected light beams are reflected on the reflecting surface and all the reflected light is generated as near-field light, the near-field light can be generated efficiently. Therefore, the writing reliability is high, high-density recording can be supported, and high quality can be achieved.

(First embodiment)
Hereinafter, a first embodiment of a near-field optical head and an information recording / reproducing apparatus according to the present invention will be described with reference to FIGS. Note that the information recording / reproducing apparatus 1 of the present embodiment is an apparatus for writing on a disk (magnetic recording medium) D having a perpendicular recording layer d2 by a perpendicular recording method. In the present embodiment, an air floating type in which the near-field optical head 2 is floated using the air flow rotating the disk D will be described as an example.

  As shown in FIG. 1, the information recording / reproducing apparatus 1 of this embodiment includes a near-field optical head 2 having a spot size converter (near-field light generating element) 22 described later, and a disk surface (surface of a magnetic recording medium). The near-field optical head 2 is supported on the tip side while being movable in two directions (X axis and Y axis) that are parallel to the disk surface D1 and orthogonal to each other. The suspension 3, the laser light source (light source) 5 that makes the light beam L incident on the optical fiber 4 from the base end side of the optical fiber (light flux introducing means) 4, the base end side of the suspension 3 are supported, and the suspension 3 is scanned in the X and Y directions parallel to the disk surface D1, an actuator 6 that rotates the disk D in a fixed direction, and a spindle motor (rotation drive unit) 7 that rotates the disk D in a fixed direction. Supplies to the coil 33 to be described later flow, and a control unit 8 for controlling the operation of the laser light source 5, and a housing 9 that houses the respective components therein.

  The housing 9 is made of a metal material such as aluminum and has a quadrangular shape when viewed from the top, and a recess 9a for accommodating each component is formed inside. Further, a lid (not shown) is detachably fixed to the housing 9 so as to close the opening of the recess 9a. A spindle motor 7 is attached to substantially the center of the recess 9a, and the disk D is detachably fixed by fitting a center hole into the spindle motor 7. The actuator 6 is attached to the corner of the recess 9a. A carriage 11 is attached to the actuator 6 via a bearing 10, and a suspension 3 is attached to the tip of the carriage 11. The carriage 11 and the suspension 3 constitute a rotating member 13 that can be moved in the X and Y directions by driving the actuator 6.

  The carriage 11 and the suspension 3 (the rotation member 13) are retracted from the disk D by driving the actuator 6 when the rotation of the disk D is stopped. The near-field light head 2 and the suspension 3 constitute a head gimbal assembly 12. The laser light source 5 is mounted in the recess 9 a so as to be adjacent to the actuator 6. A control unit 8 is attached adjacent to the laser light source 5.

  The near-field optical head 2 heats the rotating disk D and applies a recording magnetic field perpendicular to the disk D to cause magnetization reversal and record information. As shown in FIGS. 2 and 3, the near-field optical head 2 is disposed so as to face the disk D in a state where it floats a predetermined distance H from the disk surface D1, and has a slider 20 having a facing surface 20a facing the disk surface D1. A recording element 21 fixed to the front end surface of the slider 20 (hereinafter referred to as a side surface on the outflow end side), a spot size converter 22 fixed adjacent to the recording element 21, and the spot size The optical fiber 4 which introduces the light beam L from the laser light source 5 is provided in a core 40 described later of the converter 22. Further, the near-field optical head 2 of the present embodiment includes a reproducing element 23 fixed adjacent to the spot size converter 22.

  Here, as shown in FIG. 4, the optical fiber 4 is disposed inside the resin structure 50 on the slider 20. In the resin structure 50, the optical fiber 4 is bent halfway and connected to the spot size converter 22 obliquely from above. For example, the angle θ1 formed by the horizontal direction (XY in-plane direction) and the optical fiber 4 is set to 10 °. The optical fiber 4 is not bent in the resin structure 50, and the optical fiber 4 is linearly formed so that the angle formed between the horizontal direction (XY in-plane direction) and the optical fiber 4 is θ1. You may arrange in.

  The slider 20 is formed in a rectangular parallelepiped shape using a light-transmitting material such as quartz glass or a ceramic such as AlTiC (altic). The slider 20 is supported so as to hang from the tip of the suspension 3 via the gimbal portion 24 with the opposing surface 20a facing the disk D. The gimbal portion 24 is a component whose movement is restricted so as to be displaced only around the X axis and around the Y axis. As a result, the slider 20 is rotatable about two axes (X axis and Y axis) that are parallel to the disk surface D1 and orthogonal to each other as described above.

  On the opposing surface 20 a of the slider 20, a ridge portion 20 b is formed that generates pressure for rising due to the viscosity of the air flow generated by the rotating disk D. In this embodiment, the case where the two protruding item | lines parts 20b extended along the longitudinal direction are formed so that it may rank with a rail shape is made into the example. However, the present invention is not limited to this case, and the slider 20 is optimally adjusted by adjusting the positive pressure for separating the slider 20 from the disk surface D1 and the negative pressure for attracting the slider 20 to the disk surface D1. Any irregular shape may be used as long as it is designed to float in a state. In addition, the surface of this protruding item | line part 20b is made into the surface called ABS (Air Bearing Surface).

  The slider 20 receives a force that rises from the disk surface D1 by the two ridges 20b. The suspension 3 bends in the Z direction perpendicular to the disk surface D1, and absorbs the flying force of the slider 20. That is, the slider 20 receives a force pressed against the disk surface D1 side by the suspension 3 when it floats. Therefore, the slider 20 floats in a state of being separated from the disk surface D1 by a predetermined distance H as described above due to the balance between the forces of the two. Moreover, since the slider 20 is rotated about the X axis and the Y axis by the gimbal portion 24, the slider 20 always floats in a stable posture. The air flow generated along with the rotation of the disk D flows from the inflow end side of the slider 20 (the base end side of the suspension 3), then flows along the ABS, and flows out of the slider 20 at the outflow end side (the tip of the suspension 3). Side).

  As shown in FIG. 4, the recording element 21 is connected to the auxiliary magnetic pole 30 fixed to the side surface on the outflow end side of the slider 20 and the auxiliary magnetic pole 30 via the magnetic circuit 31 and is perpendicular to the disk D. A main magnetic pole 32 that generates a magnetic field with the auxiliary magnetic pole 30 and a coil 33 that spirally winds around the magnetic circuit 31 around the magnetic circuit 31 are provided. That is, the auxiliary magnetic pole 30, the magnetic circuit 31, the coil 33, and the main magnetic pole 32 are arranged in order from the outflow end side of the slider 20.

  The auxiliary magnetic pole 30, the main magnetic pole 32, and the magnetic circuit 31 are formed of a high saturation magnetic flux density (Bs) material (for example, a CoNiFe alloy, a CoFe alloy, etc.) having a high magnetic flux density. Further, the coil 33 is arranged so that there is a gap between adjacent coil wires, between the magnetic circuit 31 and between the magnetic poles 30 and 32 so as not to be short-circuited. Molded. The coil 33 is supplied with a current modulated according to information from the control unit 8. That is, the magnetic circuit 31 and the coil 33 constitute an electromagnet as a whole. The main magnetic pole 32 and the auxiliary magnetic pole 30 are designed so that the end surfaces facing the disk D are flush with the ABS of the slider 20.

  The spot size converter 22 is fixed adjacent to the recording element 21 with one end side facing the upper side of the slider 20 and the other end side facing the disk D side. More specifically, it is fixed adjacent to the main pole 32.

The spot size converter 22 is an element that propagates the light beam L introduced to one end side while condensing to the other end side in a direction different from the introduction direction, and generates the near-field light R and then emits it to the outside. As shown in FIGS. 4 to 8, the polyhedron core 40 and a clad 41 for confining the core 40 are formed in a substantially plate shape as a whole.
5 is an enlarged view of the other end side of the spot size converter 22 shown in FIG. 4, and FIG. 6 is an enlarged view of the other end side of the core 40 shown in FIG. 5 (an arrow view from the direction A). FIG. 7 is a view of the spot size converter 22 shown in FIG. 5 as viewed from the end face 40d side.

  As shown in FIG. 4, the core 40 is integrally formed by a reflecting surface 40a, a light beam condensing unit 40b, and a near-field light generating unit 40c. In the present embodiment, the light beam condensing unit 40b and the near-field light generating unit 40c are each formed to have three side surfaces, and one of the side surfaces is arranged to face the main magnetic pole 32. Yes.

The reflection surface 40a reflects the light beam L introduced by the optical fiber 4 from one end side in a direction different from the introduction direction.
The light beam condensing part 40b is a portion formed by drawing so that the cross-sectional area perpendicular to the longitudinal direction (Z direction) from one end side to the other end side gradually decreases, and the light beam reflected by the reflecting surface 40a. L is condensed and propagated toward the other end side. That is, the light beam condensing unit 40b can reduce the spot size of the introduced light beam L to a small size. Here, as shown in FIG. 8, the light beam L reflected by the reflecting surface 40a and propagated to the light beam condensing unit 40b is not all propagated to the near-field light generating unit 40c. Only the light beam L incident on the receivable surface 40f, which is a part of the entrance surface 40e, is guided to the near-field light generation unit 40c.

The near-field light generating unit 40c is a part that is further drawn from the end of the light beam condensing unit 40b toward the other end. That is, the near-field light generating unit 40c can further reduce the spot size narrowed down by the light beam condensing unit 40b. At this time, as shown in FIG. 7, the near-field light generating unit 40c is drawn so that the end surface 40d located on the other end side has a size equal to or smaller than the wavelength of light. That is, the maximum linear length L1 that can be secured on the end face 40d is designed to be equal to or less than the wavelength of light. In addition, it is preferable to set it as the range below 1 nm of this light wavelength, More preferably, it is the range of 1 nm to 500 nm.
As a result, the spot size can be reduced to the same size as the maximum linear length L1, that is, the diameter can be reduced to about 1 nm to 1 μm (or about 1 nm to 500 nm), and the near-field light R of this size (FIG. 4). Reference) can be emitted from the end face 40d to the outside.

  In the present embodiment, the light beam condensing unit 40b and the near-field light generating unit 40c are both gradually drawn toward the main magnetic pole 32 as shown in FIG. Thereby, the end face 40d is positioned on the main magnetic pole 32 side. As a result, the near-field light R having the above size can be generated in the vicinity of the main magnetic pole 32. The term “near” in the present embodiment refers to a region within a range separated from the main magnetic pole 32 by a distance approximately equal to or less than the diameter of the near-field light R generated from the end face 40d. . Therefore, in the case of the present embodiment, the distance between the main magnetic pole 32 and the end face 40d of the near-field light generating unit 40c is about 1 nm to 1 μm, which is about the same as the diameter (maximum linear length L1) of the near-field light R ( (Alternatively, the distance is about 1 nm to 500 nm) or less.

  As shown in FIG. 4, the clad 41 is made of a material having a refractive index lower than that of the core 40, and is in close contact with the side surface of the core 40 to confine the core 40 inside. Therefore, no gap is generated between the core 40 and the clad 41. Also, the clad 41 of the present embodiment is formed so that the end face 40d on the other end side is exposed to the outside, like the one end side of the core 40.

An example of a combination of materials used as the clad 41 and the core 40 is described, for example, a combination in which the core 40 is formed from quartz (SiO ₂ ) and the clad 41 is formed from quartz doped with fluorine. In this case, when the wavelength of the light beam L is 400 nm, the refractive index of the core 40 is 1.47, and the refractive index of the clad 41 is less than 1.47, which is a preferable combination. A combination in which the core 40 is formed of quartz doped with germanium and the cladding 41 is formed of quartz (SiO ₂ ) is also conceivable. In this case, when the wavelength of the light beam L is 400 nm, the refractive index of the core 40 becomes larger than 1.47, and the refractive index of the clad 41 becomes 1.47.

In particular, the larger the refractive index difference between the core 40 and the cladding 41, the force to confine the light beam L in the core 40 increases, tantalum oxide core 40 (Ta ₂ O _5: refractive index at a wavelength of 550nm is 2.16) and using quartz or the like for the clad 41 to increase the difference in refractive index between the two is more preferable. In addition, when the luminous flux L in the infrared region is used, it is also effective to form the core 40 with silicon (Si: refractive index is about 4) which is a material transparent to infrared light.

  A light shielding film 42 that shields the light flux L is formed on two surfaces of the three side surfaces of the near-field light generating unit 40 c except for one side surface that faces the main magnetic pole 32. As a result, the light flux L does not leak from the near-field light generator 40c to the clad 41 side. The near-field light generating unit 40c can generate the near-field light R from the light beam L collected by the light beam condensing unit 40b and emit it from the end face 40d to the outside by the light shielding film 42 and the above-described aperture forming. It is like that. Moreover, since the end face 40d is formed on the main magnetic pole 32 side, the near-field light R can be generated in the vicinity of the main magnetic pole 32. The end face 40d of the spot size converter 22 is designed to be flush with the ABS of the slider 20.

  As shown in FIG. 4, the optical fiber 4 includes a core 4a and a clad 4b, and a light beam L propagates through the core 4a. The tip of the optical fiber 4 is connected to one end side of the spot size converter 22 and introduces the light beam L into the core 40. The proximal end side of the optical fiber 4 is connected to the laser light source 5 via the suspension 3 and the carriage 11.

Here, as shown in FIG. 4, the light with respect to the spot size converter 22 is so reflected that the light beam L introduced into the core 40 from the optical fiber 4 is totally reflected by the reflecting surface 40a and guided to the light beam condensing unit 40b. The positional relationship of the fiber 4 is adjusted. Specifically, the optical fiber 4 is inclined so that an angle θ1 = 10 ° between the optical fiber 4 and the opposed surface 20a of the slider 20 (the upper surface of the slider 20) (details will be described later). Here, the light beam L refers to light within the spot diameter of the light beam. The spot diameter generally means within a range of 1 / e ² (about 13.5%, e is the base of natural logarithm) of the central light intensity.

  The reproducing element 23 is a magnetoresistive film whose electric resistance is converted according to the magnitude of the magnetic field leaking from the perpendicular recording layer d2 of the disk D. A bias current is supplied to the reproducing element 23 from the control unit 8 via a lead film (not shown). Thus, the control unit 8 can detect a change in the magnetic field leaking from the disk D as a change in voltage, and can reproduce a signal from the change in voltage.

  The disk D of the present embodiment is a perpendicular structure composed of at least two layers: a perpendicular recording layer d2 having an easy axis in the direction perpendicular to the disk surface D1, and a soft magnetic layer d3 made of a high magnetic permeability material. A bilayer disc is used. As such a disk D, for example, as shown in FIG. 2, a soft magnetic layer d3, an intermediate layer d4, a perpendicular recording layer d2, a protective layer d5, and a lubricating layer d6 are sequentially formed on a substrate d1. Use the film.

  Examples of the substrate d1 include an aluminum substrate and a glass substrate. The soft magnetic layer d3 is a high magnetic permeability layer. The intermediate layer d4 is a crystal control layer of the perpendicular recording layer d2. The perpendicular recording layer d2 is a perpendicular anisotropic magnetic layer, and for example, a CoCrPt alloy is used. The protective layer d5 is for protecting the perpendicular recording layer d2, and for example, a DLC (Diamond Like Carbon) film is used. For the lubrication layer d6, for example, a fluorine-based liquid lubricant is used.

Next, a case where various kinds of information is recorded / reproduced on / from the disk D by the information recording / reproducing apparatus 1 configured as described above will be described below.
First, the spindle motor 7 is driven to rotate the disk D in a certain direction. Next, the actuator 6 is operated to scan the suspension 3 in the XY directions via the carriage 11. As a result, the near-field optical head 2 can be positioned at a desired position on the disk D as shown in FIG. At this time, the near-field optical head 2 receives a force that rises by the two protruding portions 20b formed on the opposing surface 20a of the slider 20 and is pressed against the disk D side with a predetermined force by the suspension 3 or the like. The near-field optical head 2 floats to a position separated by a predetermined distance H from the disk D as shown in FIG.

  Even if the near-field optical head 2 receives the wind pressure generated due to the undulation of the disk D, the suspension 3 absorbs the displacement in the Z direction and is displaced around the XY axis by the gimbal portion 24. Therefore, the wind pressure caused by the swell can be absorbed. Therefore, the near-field light head 2 can be floated in a stable state.

Here, when recording information, the control unit 8 operates the laser light source 5 and supplies the coil 33 with a current modulated according to the information.
First, in response to an instruction from the control unit 8, the laser light source 5 causes the light beam L to enter from the proximal end side of the optical fiber 4. As shown in FIG. 4, the incident light beam L travels in the core 4 a of the optical fiber 4 toward the tip side, and is introduced into the core 40 from one end side of the spot size converter 22. Here, in the present embodiment, the optical fiber 4 for the spot size converter 22 is such that the light beam L introduced from the optical fiber 4 into the core 40 is totally reflected by the reflecting surface 40a and guided to the light beam condensing unit 40b. The connection angle (the angle formed between the optical fiber 4 and the facing surface 20a of the slider 20) is a predetermined angle θ1 (= 10 °). At this time, the light beam L is introduced into the core 40 from a direction inclined by a predetermined angle θ1 with respect to the facing surface 20a of the slider 20.
Then, the light beam L introduced into the core 40 is totally reflected by the reflecting surface 40a and changes its direction. That is, all the light beams L have an incident angle θ2 of 41 ° or more with respect to the reflecting surface 40a, are totally reflected on the reflecting surface 40a, and the direction of the light beams L changes in a direction different from the introduction direction. Then, the light beam L whose direction has changed is totally reflected inside the light beam condensing unit 40b when the incident angle θ3 (see FIG. 9) with respect to the entrance surface 40e of the light beam condensing unit 40b is incident at a predetermined angle or less. Then, it propagates while being collected and enters the near-field light generation unit 40c. Therefore, the near-field light R can be generated with high efficiency.

  Incidentally, as shown in FIG. 10, when the angle θ4 formed by the optical fiber 4 and the facing surface 20a of the slider 20 (the upper surface of the slider 2) is 20 °, all the light beams L are reflected with respect to the reflecting surface 40a. Although the incident angle θ5 is 41 ° or more and is totally reflected at the reflecting surface 40a, a part of the reflected light is an angle at which the incident angle θ6 with respect to the entrance surface 40e of the light beam collecting part 40b is larger than a predetermined angle. Will be incident. Then, the light having the incident angle θ6 larger than the predetermined angle is leaked from the core 40 as a refracted and transmitted light component without being totally reflected by the light beam condensing unit 40b. That is, since the amount of light incident on the near-field light generation unit 40c is reduced, the generation efficiency of the near-field light R is reduced.

  Further, the light beam condensing part 40b is drawn so that the cross-sectional area perpendicular to the longitudinal direction from one end side to the other end side gradually decreases. Therefore, when the light beam L passes through the light beam condensing part 40b, it is gradually condensed while being reflected on the side surface, and propagates through the core 40. In particular, since the clad 41 is in close contact with the side surface of the core 40, light does not leak to the outside of the core 40, and the introduced light beam L can be propagated to the other end side without being wasted. .

  Then, the light beam L propagated to the end portion on the other end side of the light beam condensing unit 40b subsequently enters the near-field light generating unit 40c. The near-field light generating unit 40c is further drawn toward the other end, and the end surface 40d has a size equal to or smaller than the light wavelength. In addition, the two side surfaces of the near-field light generating unit 40 c are shielded from light by the light shielding film 42. Therefore, the light beam L incident on the near-field light generation unit 40c can be propagated toward the end face 40d without leaking to the clad 41 side. Therefore, the near-field light R can be generated with high efficiency, and the near-field light R can be emitted to the outside from the end face 40d.

  Due to the near-field light R, the disk D is locally heated and the coercivity is temporarily reduced. In particular, the near-field light generation unit 40c generates the near-field light R in the vicinity of the main magnetic pole 32, that is, in a range separated from the main magnetic pole 32 by a distance approximately equal to the diameter of the near-field light R. The coercive force of the disk D can be reduced as close as possible to the magnetic pole 32.

  On the other hand, when a current is supplied to the coil 33 by the control unit 8, the current magnetic field generates a magnetic field in the magnetic circuit 31 according to the principle of the electromagnet, so that the disk D is interposed between the main magnetic pole 32 and the auxiliary magnetic pole 30. A perpendicular recording magnetic field can be generated. Then, the magnetic flux generated from the main magnetic pole 32 side passes straight through the perpendicular recording layer d2 of the disk D and reaches the soft magnetic layer d3 as shown in FIG. As a result, recording can be performed with the magnetization of the perpendicular recording layer d2 oriented perpendicularly to the disk surface D1. The magnetic flux that has reached the soft magnetic layer d3 returns to the auxiliary magnetic pole 30 via the soft magnetic layer d3. At this time, when returning to the auxiliary magnetic pole 30, the magnetization direction is not affected. This is because the area of the auxiliary magnetic pole 30 facing the disk surface D1 is larger than that of the main magnetic pole 32, so that the magnetic flux density is large and a force sufficient to reverse the magnetization does not occur. That is, recording can be performed only on the main magnetic pole 32 side.

As a result, information can be recorded by the near-field light assisted magnetic recording method in which the near-field light R and the recording magnetic fields generated by the magnetic poles 30 and 32 cooperate. In addition, since the recording is performed by the vertical recording method, it is difficult to be affected by the thermal fluctuation phenomenon, and stable recording can be performed. Therefore, writing reliability can be improved.
Further, since the coercive force of the disk D can be reduced in the vicinity of the main magnetic pole 32, the peak position of the heating temperature can be set at a position where the recording magnetic field acts locally. Therefore, recording can be performed reliably, reliability can be improved, and high density recording can be achieved.

  Next, when reproducing the information recorded on the disc D, the reproducing element 23 fixed adjacent to the spot size converter 22 receives the magnetic field leaking from the perpendicular recording layer d2 of the disc D. Thus, the electrical resistance changes according to the size. Therefore, the voltage of the reproducing element 23 changes. Thereby, the control unit 8 can detect a change in the magnetic field leaking from the disk D as a change in voltage. And the control part 8 can reproduce | regenerate information by reproducing | regenerating a signal from the change of this voltage.

  As described above, the near-field optical head 2 of the present embodiment includes the spot size converter 22 that can efficiently generate the near-field light R, and thus the writing reliability of the near-field optical head 2 itself. Can be improved, and quality can be improved. In addition, in this embodiment, since the clad 41 is formed with the end face 40d on the one end side and the other end side of the core 40 exposed to the outside, the light flux L is directly introduced into the core 40 without passing through the clad 41. In addition, it can be converted into near-field light R more efficiently and emitted from the end face 40d to the outside.

  In particular, the spot size converter 22 can change the direction of the introduced light beam L by reflecting it with the reflecting surface 40a. Therefore, even if the optical fiber 4 is arranged along the upper surface of the slider 20, the optical fiber 4 can be converted into near-field light R in the vicinity of the main magnetic pole 32. Therefore, the design of the near-field optical head 2 can be made compact. Moreover, since it is not necessary to propagate the light beam L in the air, the light guide loss can be reduced as much as possible. Further, since the recording element 21, the spot size converter 22 and the reproducing element 23 are sequentially arranged on the side surface on the outflow end side of the slider 20, each component other than the optical fiber 4 overlaps in the thickness direction of the slider 20. Is preventing. Therefore, the near-field optical head 2 itself can be thinned.

  Moreover, when manufacturing the near-field optical head 2 of this embodiment, it can manufacture using semiconductor techniques, such as a photolithographic technique and an etching process technique. That is, even when the spot size converter 22 is provided, the spot size converter 22 can be simultaneously formed in the flow of the conventional manufacturing process without using a special method.

More specifically, after the slider 20 is processed into a predetermined outer shape, the recording element 21 is formed on the side surface on the outflow end side of the slider 20 using the semiconductor technology.
In addition, a spot size converter 22 is formed separately. At this time, a member constituting the clad 41 is formed, and a resist is formed on the clad 41. The resist is patterned corresponding to the groove for forming the core 40, and the groove is formed in the clad 41 by isotropic etching. And the core 40 (The reflective surface 40a, the light beam condensing part 40b, and the near-field light generation part 40c) is formed in a groove part. Moreover, the end surface 40d can be formed by cutting the other end side of the spot size converter 22 by dicing or the like. In this way, the spot size converter 22 can be easily manufactured using semiconductor technology.
The spot size converter 22 thus formed is arranged on the recording element 21. Finally, the reproducing element 23 may be formed on the spot size converter 22. Thus, the near-field optical head 2 can be manufactured easily.

  According to the present embodiment, the angle θ1 (angle formed between the optical fiber 4 and the optical axis of the spot size converter 22) formed between the optical fiber 4 and the facing surface 20a of the slider 20 is adjusted to Since the light beam L introduced into the core 40 of the spot size converter 22 is totally reflected on the reflecting surface 40a, and all of the reflected light is guided from the light beam condensing unit 40b to the near-field light generating unit 40c. The near-field light R can be generated efficiently.

  Further, the vicinity of the end of the optical fiber 4 connected to the spot size converter 22 is accommodated in a resin structure 50 that can be placed on the upper surface of the slider 20, and the optical fiber 4 is connected to the slider 20 in the resin structure 50. Since it is held (fixed) while being inclined (θ1 = 10 °) with respect to the facing surface 20a (the upper surface of the slider 20), the arrangement angle of the optical fiber 4 with respect to the core 40a of the spot size converter 22 can be easily Can be fixed securely.

In addition, according to the information recording / reproducing apparatus 1 of the present embodiment, since the near-field optical head 2 described above is provided, the writing reliability is high, high-density recording can be supported, and high quality can be achieved. Can be planned.
In the above-described embodiment, it is preferable to introduce the light beam L into the optical fiber 4 after adjusting the polarization component of the light beam L in the arrow L2 direction shown in FIG. By doing so, the near-field light R can be concentrated in the vicinity of the side surface (region S shown in FIG. 7) of the near-field light generation unit 40c facing the main magnetic pole 32 side. Therefore, higher density recording can be achieved.

(Second embodiment)
The second embodiment of the near-field optical head and information recording / reproducing apparatus according to the present invention will be described below with reference to FIGS. The present embodiment is different from the first embodiment only in the configuration of the optical waveguide (optical fiber) and the method of supporting the slider, and the other configurations are substantially the same. Detailed description will be omitted.
As shown in FIGS. 11 to 13, a slope base 60 having a slope 60 a is disposed on the upper surface of the slider 20. The inclined surface 60a is formed to have a downward gradient toward the spot size converter 22 (core 40), and the inclination angle θ1 is 10 °. An optical waveguide 54 is formed along the upper surface of the slope base 60. That is, the optical waveguide 54 is bent halfway on the slope base 60 and is connected to the spot size converter 22 obliquely from above. The optical waveguide 54 may be formed in a straight line so that the angle formed by the horizontal direction (XY in-plane direction) and the optical waveguide 54 is θ1 without being bent on the slope base 60. . Alternatively, the inclined surface 60a may be formed directly on the upper surface of the slider 20, and the inclined surface 60 may not be disposed separately.

When the optical waveguide 54 is manufactured, the optical waveguide 54 can be easily manufactured by using a semiconductor technique such as a photolithography technique and an etching processing technique. The optical waveguide 54 includes a core 54a and a clad 54b.
An example of a combination of materials used as the core 54a and the clad 54b is described. For example, a combination in which the core 54a is formed of quartz (SiO ₂ ) and the clad 54b is formed of quartz doped with fluorine can be considered. In this case, when the wavelength of the light beam L is 400 nm, the refractive index of the core 54a is 1.47, and the refractive index of the clad 54b is less than 1.47, which is a preferable combination. A combination in which the core 54a is formed of quartz doped with germanium and the clad 54b is formed of quartz (SiO ₂ ) is also conceivable. In this case, when the wavelength of the light beam L is 400 nm, the refractive index of the core 54a is larger than 1.47, and the refractive index of the clad 54b is 1.47.

In particular, the greater the difference in refractive index between the core 54a and the clad 54b, the greater the force for confining the light beam L in the core 54a, so that the core 54a has a refractive index of tantalum oxide (Ta ₂ O ₅ : wavelength is 550 nm). 2.16) and using quartz or the like for the clad 54b to increase the refractive index difference between the two is more preferable. Further, when using the light flux L in the infrared region, it is also effective to form the core 54a with silicon (Si: refractive index is about 4) which is a material transparent to infrared light.

  According to this embodiment, the light flux introduced from the optical waveguide 54 to the core 40 of the spot size converter 22 by adjusting the angle θ1 formed between the optical waveguide 54 and the spot size converter 22 (the upper surface of the slider 2). Since L is totally reflected on the reflecting surface 40a and all of the reflected light is guided from the light beam condensing unit 40b to the near-field light generating unit 40c, the near-field light R can be generated efficiently. .

  Further, the vicinity of the end of the optical waveguide 54 connected to the spot size converter 22 is formed on a slope base 60 formed on the upper surface of the slider 20, and the optical waveguide 54 is inclined with respect to the upper surface of the slider 20 (θ1 = 10 degrees), the arrangement angle of the optical waveguide 54 can be easily and reliably fixed with respect to the core 40 of the spot size converter 22.

  Further, according to the information recording / reproducing apparatus 1 of the present embodiment, since the near-field light head 2 capable of generating the near-field light R with high efficiency is provided, the writing reliability is high and high-density recording is supported. It is possible to improve the quality.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the spot size converter 22 is applied to the near-field light head 2 has been described as an example. It may be applied to the device. In particular, in the above-described embodiment, the applied light beam L is designed so that the direction of the introduced light beam L changes at the reflecting surface 40a when applied to the near-field light head 2, but the reflection angle is not limited to the predetermined angle θ1.

In the above embodiment, only two of the three side surfaces of the near-field light generating unit 40c are shielded by the light shielding film 42. However, at least one side surface may be shielded. Even in this case, the near-field light R can be generated.
However, it is preferable to shield all side surfaces (three side surfaces) with the light shielding film 42. By doing so, it is possible to more reliably prevent the light beam L incident on the near-field light generating unit 40c from leaking to the clad 41 side. Therefore, the loss of the light flux L can be minimized, and the near-field light R can be generated more efficiently.

  In each of the above embodiments, the air floating type information recording / reproducing apparatus 1 in which the near-field optical head 2 is levitated has been described as an example. However, the present invention is not limited to this, and the information recording / reproducing apparatus 1 may be disposed to face the disk surface D1. For example, the disk D and the slider 20 may be in contact with each other. That is, the near-field optical head 2 according to the present invention may be a contact slider type head. Even in this case, the same effects can be achieved.

Furthermore, in the above-described embodiment, the case of the near-field optical head 2 of the vertical recording system has been described, but the present invention can also be applied to a near-field optical head of the horizontal recording system.
In addition to the structure of the near-field light head of the above-described embodiment, as shown in FIG. It can also be used for a core having a straight structure 240 having the same area.

It is a block diagram which shows the information recording / reproducing apparatus in embodiment of this invention. It is an expanded sectional view of the near-field optical head shown in FIG. FIG. 3 is a diagram of the near-field optical head shown in FIG. 2 viewed from the disk surface side. FIG. 3 is an enlarged cross-sectional view of the side surface on the outflow end side of the near-field optical head shown in FIG. 2, showing the configuration of the spot size converter and the recording element, and the relationship between the near-field light and the magnetic field during recording. FIG. It is the figure which expanded the other end side of the spot size converter shown in FIG. It is the figure which looked at the core of the spot size converter shown in FIG. 5 from the arrow A direction. It is the figure which looked at the spot size converter shown in FIG. 5 from the end surface side. It is a figure explaining the course of the light beam in the core in the embodiment of the present invention. It is a figure explaining the introduction direction of the light beam in embodiment of this invention. It is a figure explaining the introduction direction of a light beam when a light beam is introduced from an angle different from FIG. It is an expanded sectional view (equivalent to FIG. 2) of the near-field optical head in 2nd embodiment of this invention. It is sectional drawing which expanded the side surface by the side of the outflow end of the near-field optical head in 2nd embodiment of this invention, and shows the structure of a spot size converter and a recording element, and the near-field light at the time of performing recording, It is the figure (equivalent to FIG. 4) which showed the relationship with a magnetic field. It is a perspective view (some components are abbreviate | omitted) of the near-field optical head in 2nd embodiment of this invention. It is sectional drawing which shows another aspect which expanded the side surface by the side of the outflow end of the near-field optical head in embodiment of this invention. It is sectional drawing (equivalent to FIG. 4) which expanded the side surface by the side of the outflow end of the conventional near-field optical head. It is a figure explaining the introduction direction of the light beam at the time of using the near-field light head shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Information recording / reproducing apparatus 2 ... Near field optical head 3 ... Suspension (rotating member) 4 ... Optical fiber (light beam introduction means) 5 ... Laser light source (light source) 6 ... Actuator 7 ... Spindle motor (rotation drive part) 8 ... Control part 11 ... Carriage (turning member) 13 ... Turning member 20 ... Slider 20a ... Opposing surface (surface facing the magnetic recording medium) 22 ... Spot size converter (near-field light generating element) 24 ... Gimbal part (supporting) 40) Core 40a ... Reflecting surface 40b ... Light flux condensing part 40c ... Near-field light generating part 41 ... Cladding 50 ... Resin structure (structure) 54 ... Optical waveguide (light flux introducing means) 60a ... Slope D ... Disc ( Magnetic recording medium) D1 ... disk surface (surface of magnetic recording medium) L ... luminous flux R ... near-field light θ1 ... predetermined angle (connection angle)

Claims (5)

A near-field optical head for recording information by heating a magnetic recording medium rotating in a certain direction with near-field light and causing magnetization reversal by applying a recording magnetic field to the magnetic recording medium,
A slider disposed opposite to the surface of the magnetic recording medium;
A support member for supporting the slider;
A near-field light generating element that is mounted on the slider and generates the near-field light on the magnetic recording medium side using a light beam introduced from the support member side;
A light beam introducing means for introducing a light beam to the support member side of the near-field light generating element,
The near-field light generating element is formed of a material that transmits the light beam, and has a core having a reflection surface that reflects the light beam introduced from the light beam introducing unit toward the magnetic recording medium side, and more than the core A clad formed of a material having a low refractive index and covering the core,
The light of the light flux introducing means is directed to the surface of the slider facing the magnetic recording medium so that all of the light within the spot diameter of the light flux introduced from the light flux introducing means is reflected by the reflecting surface. A near-field optical head characterized in that an axis is inclined. The near-field light generating element is condensed with a light beam condensing unit formed such that a cross-sectional area of the core perpendicular to the optical axis gradually decreases from the support member side toward the magnetic recording medium side. A near-field light generating unit that generates the near-field light from the luminous flux,
The reflecting surface reflects the light beam introduced from the light beam introducing means toward the light beam condensing unit,
Of the luminous flux introduced from the luminous flux introducing means, all of the light within the spot diameter is reflected by the reflecting surface, and all of the reflected light is propagated inside the luminous flux condensing unit to generate the near-field light. The near-field optical head according to claim 1, wherein an optical axis of the light flux introducing unit is inclined with respect to a surface of the slider facing the magnetic recording medium so as to be guided to the portion. The vicinity of the tip connected to the near-field light generating element in the light flux introducing means is accommodated in a structure that can be placed on the upper surface of the slider,
In the structure, the light flux introducing means and the core are connected at the predetermined angle in a state where the light flux introducing means is held so as to be inclined with respect to a surface of the slider facing the magnetic recording medium. The near-field optical head according to claim 1, wherein: A slope is formed on the upper surface of the slider,
The light flux introducing means is formed on the slope,
The near-field optical head according to claim 1, wherein the light flux introducing means and the core are connected at the predetermined angle. A near-field optical head according to any one of claims 1 to 4,
A rotating member configured to be movable in a direction parallel to the surface of the magnetic recording medium, and supporting the near-field optical head on the tip side;
A light source for making the light beam incident on the light beam introducing means;
An actuator that supports the base end side of the rotating member and moves the rotating member in a direction parallel to the surface of the magnetic recording medium;
A rotation drive unit for rotating the magnetic recording medium in the fixed direction;
An information recording / reproducing apparatus comprising: a control unit that controls the operation of the light source.

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