WO2011027414A1 - Thermal-assist magnetic recording head, and slider - Google Patents

Abstract

Disclosed is a thermal-assist magnetic head having a laser-diode mounted thereon.  In order to suppress reflected return lights to a light source thereby to realize the stable actions of the light source, the thermal-assist magnetic head is provided with a slider having a waveguide, on which the mirror of a horizontal-resonator perpendicular-emission LD is mounted.  The taper angle of the mirror plane of the horizontal-resonator perpendicular-emission LD is deviated from 45 degrees.

Description

Thermally assisted magnetic recording head and slider

This invention relates to a heat-assisted magnetic recording head that assists magnetic recording with heat from laser light.

As one of information recording devices, a magnetic disk device mounted on a computer or the like is required to have a high recording density in order to store a large amount of information without increasing the size of the device. In order to increase the density of a magnetic disk, a recording medium having a high coercive force is used because it is necessary to stabilize minute recording bits. In order to record on a recording medium having a high coercive force, it is necessary to concentrate a strong magnetic field strength on a minute area. However, it is technically difficult to concentrate a strong magnetic field strength on a minute region.

As a technology for solving this problem, hybrid recording technology that combines optical recording technology and magnetic recording technology is considered promising. During recording, the medium is heated with light simultaneously with the applied magnetic field to reduce the coercivity of the medium. This facilitates recording on a recording medium with high coercive force, which has been difficult to record due to insufficient recording magnetic field strength in the conventional magnetic recording head. Reproduction uses the magnetoresistive effect used in conventional magnetic recording. This hybrid recording method is called thermally assisted magnetic recording or optically assisted magnetic recording.

In this thermally assisted magnetic recording system, a laser beam for heating the medium is guided to the recording head. As the laser light source, a small-sized and low power consumption semiconductor laser diode (hereinafter referred to as LD) is used because it is necessary to use it in a package of a magnetic disk device.

In order to obtain sufficient light intensity required for recording, it is necessary to increase the light intensity generated by the LD or reduce the propagation loss. Since the optical output of the LD is finite and closely related to the size and life of the LD, it is not desirable to increase only the light intensity.

Therefore, it is necessary to efficiently guide the light generated from the semiconductor laser to the tip of the head, that is, to reduce the propagation loss. As a structure that realizes such a requirement, Patent Document 1 describes an integrated head on which a vertical emission LD of a horizontal resonator in which reflectors are monolithically integrated is mounted.

JP 2008-59645 A

In the heat-assisted magnetic recording head of Patent Document 1, in order to reduce optical loss, optical components are integrated to minimize the number of locations that require optical connection and to shorten the optical path from the light source to the recording medium. Thus, the optical loss is reduced.

However, when light passes between substances having different refractive indexes, such as at least a connection point of components, reflection of guided light occurs. The reflection is not only an optical loss, but when returning to the waveguide path through which the reflected light has propagated, it eventually returns to the inside of the LD. Light that returns to the inside of the LD due to such reflection is called reflected return light. The reflected return light has a different phase from the mode oscillating inside the LD, and when such reflected return light having a different phase returns inside the LD, it interferes with the original oscillation mode, and the optical output inside the LD fluctuates and operates. Becomes unstable.

Reflected return light is a phenomenon known in devices using a semiconductor LD as a light source, such as an optical disk drive or an optical transmitter for optical communication. In these fields, in order to prevent reflected return light, for example, the connection end face of the component in the optical path is slightly inclined from the direction perpendicular to the light traveling direction to deflect the reflected light. Inserting the substance to be adjusted, inserting an isolator in the optical path so that the reflected return light does not pass even if it comes back, high-frequency superimposition so that the return light returns to the inside of the LD, and the operation of the LD is not seen, etc. Various measures are taken.

As disclosed in Patent Document 1, in a thermally assisted magnetic recording head equipped with an LD, similarly, since a lateral single mode semiconductor LD is used as a light source, the reflected return light becomes a problem.

FIG. 1 is an enlarged sectional view of the vicinity of a heat-assisted magnetic recording head of a conventional magnetic disk device.

A horizontal resonator vertical emission type semiconductor LD 100 in which a reflecting mirror 104 having a 45 degree tapered surface is monolithically integrated is mounted on a slider 110. Laser light emitted from the horizontal resonator vertical emission type semiconductor LD passes through the optical waveguide 111 in the slider 110 and reaches the magnetic recording medium (magnetic disk) 120. The arrow is the optical path.

In the horizontal resonator vertical emission type LD100, the laser beam 201 generated by the active layer 101 is reflected by the reflecting mirror 104, and the reflected laser beam 202 is perpendicular to the slider 110 side surface of the horizontal resonator vertical emission type LD100. To reach.

The laser beam 202 that has reached the slider 110 side surface of the horizontal resonator vertical emission type LD is reflected by the laser beam 203 emitted from the slider 110 side surface of the horizontal resonator vertical emission type LD to reflect the horizontal resonator vertical emission type LD. The laser beam 211 is returned to the inside. At this time, in principle, the laser beams 203 and 211 are emitted or reflected perpendicularly to the slider 110 side surface of the horizontal resonator vertical emission type LD100. If the amount of the laser beam 211 returning to the inside of the horizontal resonator vertical emission type LD is not controlled, the laser beam amplification inside the LD is not performed and the laser oscillation characteristic is impaired. For this reason, a normal reflectance control film 105 is provided on the surface of the horizontal resonator vertical emission type LD to control the amount of the laser beam 211 that returns to the inside of the horizontal resonator vertical emission type LD.

Laser light 203 emitted from the slider 110 side surface of the horizontal resonator vertical emission type LD 100 reaches the upper surface of the slider 110 and enters an optical waveguide 111 provided so as to penetrate the thickness direction of the slider 110. At this time, reflection occurs on the upper surface of the slider 110 (the upper surface of the optical waveguide 111), and a certain percentage of laser light becomes reflected return light 212.

The laser beam 204 incident (optically coupled) to the optical waveguide 111 of the slider 110 propagates through the optical waveguide 111 and reaches the lower surface (ABS: Air Bearing Surface) of the slider 110. At this time, most of the laser light is transmitted through the lower surface (ABS) of the slider 110, but a certain proportion of the laser light is reflected by the lower surface of the slider 110 and becomes reflected return light 213.

The laser beam 205 emitted from the lower surface of the slider 110 reaches the recording medium 120. At this time, most of the laser light is absorbed by the magnetic recording medium 120, but a certain proportion of the laser light is reflected by the recording medium without being absorbed, and becomes reflected return light 214.

In this way, in the optical path from the horizontal resonator vertical emission type LD to the recording medium 120, three reflections are made: the upper surface of the slider 110, the lower surface (ABS) of the slider 110, and the surface of the recording medium (magnetic disk) 120. There is a point.

The reflected return light 212, 213, 214 has a certain ratio that travels backward in the optical path through which the laser light has propagated and returns to the inside of the horizontal resonator vertical emission type LD100 to stabilize the operation of the horizontal resonator vertical emission type LD100. Cause damage. Therefore, a structure for suppressing the reflected return light is required at each light incident surface.

The cause of reflection occurring at the contact point of the optical component is a change in the effective refractive index of the optical path through which the light passes. In general, a structure for preventing reflection itself can reduce the reflectance by adjusting the refractive index by coating an antireflection thin film having a predetermined thickness according to the wavelength in the substance of light.

However, when the oscillation wavelength of the horizontal resonator vertical emission type LD changes due to a change in temperature, the optimum thickness of the coating film that lowers the reflectivity differs depending on the wavelength, so that reflection is not suppressed. Assuming operation in a wide temperature range such as a magnetic disk device, the wavelength changes with the temperature change of the horizontal resonator vertical emission type LD, so that reflection may not be suppressed. In addition, an antireflection film cannot always be formed due to structural and manufacturing limitations.

Therefore, it was considered to take a method of uniformly reducing the feedback rate of the reflected light with respect to the changing wavelength by controlling the incident angle. The inventors have attempted to control the angle of incidence with the implementation. However, when mounting each component at an angle, it is very difficult to control the position and angle, and there is a possibility that the stable operation of the horizontal resonator vertical emission type LD by reflected light may be impaired. This makes accurate heat-assisted magnetic recording impossible.

An object of the present invention is to stabilize the operation of a magnetic disk device and improve recording accuracy by realizing a thermally assisted magnetic recording head to which a return light suppression structure different from the conventional return light suppression structure is applied. is there.

Conventionally, the reflection surface of a horizontal resonator vertical emission type LD, which is an optical waveguide with gain used in a thermally assisted magnetic recording head, has a normal direction to the laminated surface of the semiconductor layer constituting the horizontal resonator vertical emission type LD and the resonance direction. A surface obtained by rotating the laminated surface by 45 degrees or 135 degrees about the intersecting line with the surface is used. That is, the XY plane having <X, Y, Z> = <0, 0, n> as a normal line is defined as a stacked surface of the semiconductor layers constituting the horizontal resonator vertical emission type LD, and the resonance direction is set to <X, Y, When Z> = <l, 0,0>, a surface having a normal line such that <X, Y, Z> = <n, 0, n> or <−n, 0, −n>, that is, The (n, 0, n) plane or the (−n, 0, −n) plane constitutes the reflecting surface. Note that n is a positive integer.

The present inventors considered shifting the direction of the reflecting surface to shift the optical axis of the reflected light from the optical axis of the incident light. That is, the (n, 0, n) plane and the (−n, 0, −n) plane (n ≠ 0) are not used.

By using a horizontal resonator vertical emission type LD having such a reflective surface for a thermally-assisted magnetic recording head, even if the thermally-assisted magnetic recording head is mounted substantially horizontally on the slider as in the past, the upper surface of the slider Since laser light can be incident at an angle that is not perpendicular to the (horizontal incident surface of the optical waveguide), the return light (212 in FIG. 1) is incident on the LD resonator on the upper surface of the slider. Can be suppressed. Therefore, stable operation of the horizontal resonator vertical emission type LD can be realized, and in turn, accurate magnetic recording of the heat-assisted magnetic recording head can be realized.

In particular, the reflecting surface of the horizontal resonator vertical emission type LD used for the thermally assisted magnetic recording head is centered on a line intersecting the lower surface of the horizontal resonator vertical emission type LD and the surface normal to the resonance direction. A conventional reflecting surface obtained by rotating the lower surface of the horizontal resonator vertical emission type LD by 45 degrees is further rotated by θ degrees to obtain a surface of 45 + θ degrees (the absolute value of θ <45, θ ≠ 0) degrees or 135 + θ (Absolute value of θ <45, θ ≠ 0) is preferable. That is, an XY plane having (X, Y, Z) = (0, 0, n) as a normal line is defined as a stacked surface of the semiconductor layers constituting the horizontal resonator vertical emission type LD, and the resonance direction is defined as (X, Y , Z) = (l, 0, 0), “(X, Y, Z) = (l, 0, n) or (−1, 0, −n)” and “l ≠ n” It is preferable that the reflecting surface is constituted by a surface having a normal line. When forming the reflective surface, the reflective surface can be formed by shaving a semiconductor layer in a region having a boundary line perpendicular to the resonance direction by a predetermined angle, thereby facilitating the design of mask shape and process conditions, and reproducibility. This is because a reflecting surface of a high horizontal resonator vertical emission type LD can be formed.

In addition, although the horizontal resonator vertical emission type LD in which the reflecting surface is monolithically integrated has been described so far, this can also be said to be a structure in which the reflecting surface is integrated in an optical waveguide having a gain region. However, as long as the above principle is used, a combination of a passive optical waveguide having no gain region and a reflecting mirror may be used.

Furthermore, the present inventors also examined the oblique arrangement of the optical waveguide arranged on the lower surface of the slider. As a result, the return light 212, 213 is obtained by using a slider having an optical waveguide connecting the lower surface and the upper surface and having the extension direction of the optical waveguide shifted by a predetermined angle from the normal direction of the lower surface. , 214 can be suppressed.

In order to easily and accurately manufacture a slider having such a waveguide, the side surfaces of a pair of opposing sliders also have a predetermined angle from the normal direction of the lower surface in the same manner as the extending direction of the optical waveguide. As a result of examination, it was also found that the structure to be shifted is preferable. As a manufacturing process, after manufacturing a wafer having the slider side surface as the upper surface of the wafer, dicing is not performed perpendicularly to the wafer but obliquely. Another method can be realized by changing the angle between the upper surface and the lower surface of the slider by polishing after dicing. As a result, the oblique waveguide shifted from the vertical with respect to the upper and lower surfaces of the slider can be realized by a simple process.

According to the present invention, a heat-assisted magnetic recording head with little reflected return light to the LD can be realized, the operation of the magnetic disk device can be stabilized, and the recording accuracy can be improved.

FIG. 6 is a schematic enlarged cross-sectional view in the vicinity of a heat-assisted magnetic recording head of a conventional magnetic disk device. FIG. 2 is a schematic enlarged cross-sectional view in the vicinity of a heat-assisted magnetic recording head of a magnetic disk device. It is a graph which shows the relationship between the deviation | shift amount (theta) of the angle of the reflective mirror monolithically integrated in LD, and the return rate of the light from LD surface inside. 6 is a graph showing a relationship between an angle shift amount θ of a reflecting mirror monolithically integrated in an LD and an incident angle φ on an upper surface of a slider 110; 1 is a perspective view schematically showing a magnetic disk device using a heat-assisted magnetic recording head. FIG. 3 is a schematic cross-sectional view in the vicinity of a heat-assisted magnetic recording head of a magnetic disk device. FIG. 3 is a schematic cross-sectional view in the vicinity of a heat-assisted magnetic recording head of a magnetic disk device. FIG. 3 is a schematic cross-sectional view in the vicinity of a heat-assisted magnetic recording head of a magnetic disk device.

FIG. 2 is an enlarged cross-sectional view of the vicinity of the heat-assisted magnetic recording head of the new magnetic disk device.

A horizontal resonator vertical emission type semiconductor LD 100 in which the reflecting mirror 104 is monolithically integrated is mounted on the slider 110. The laser light emitted from the horizontal resonator vertical emission type semiconductor LD 100 passes through the optical waveguide 111-1 that propagates the light in the thickness direction of the slider 110 and reaches the magnetic recording medium (magnetic disk). The optical path is indicated by an arrow. The components that the laser beam 201 generated inside the horizontal resonator vertical emission type LD 100 passes through until reaching the recording medium 120 are the same as those in FIG.

In the horizontal resonator vertical emission type LD100, the reflecting mirror 104 in which the angle with respect to the surface on which the resonator is formed, that is, the angle 301 with respect to the lower surface, which is the laminated surface of the horizontal resonator vertical emission type LD100, is shifted from 45 degrees by a predetermined angle. Are monolithically integrated. In this horizontal resonator vertical emission type LD100, the laser beam 201 generated by the active layer 101 is reflected downward by the reflecting mirror 104, and the reflected laser beam 202 is the surface of the horizontal resonator vertical emission type LD100 on the slider 110 side. To reach against.

As described above, the present inventors also examined mounting the horizontal resonator vertical emission type LD100 on the slider by inclining. The resonator of the horizontal resonator vertical emission type LD100 is formed by laminating a uniform film on a semiconductor substrate. Inclining and mounting the horizontal resonator vertical emission type LD100 with a separate member not only complicates the process, but also makes it difficult to control the angle in detail.

Therefore, as described above, the present inventors set the angle (301 in FIG. 2) of the reflector 104 monolithically integrated in the horizontal resonator vertical emission type LD100 to 45 below the lower surface of the horizontal resonator vertical emission type LD100. We considered shifting the surface set to the degree in any direction with a small angle.

First, a Fabry-Perot (FP) type LD was used as the horizontal resonator vertical emission type LD100. In the case of the FP type LD, since the resonance end is formed on the emission surface of the horizontal resonator vertical emission type LD100, even if the angle of the reflecting mirror 104 (301 in FIG. 2) is slightly deviated from 45 degrees, it is reflected on the emission surface. It is important that the amount of light returned does not decrease. However, in reality, the feedback efficiency may be drastically reduced by shifting the angle of the reflecting mirror 104. Therefore, the angle deviation was set to be minute. As a result, it was found that the light reflected from the emission surface returns to the inside of the LD and has a range that hardly affects the light emission characteristics. The range will be described below.

The reflection surface of the horizontal resonator vertical emission type LD used for the heat-assisted magnetic recording head is centered on the line intersecting the lower surface of the horizontal resonator vertical emission type LD and the surface normal to the resonance direction. A conventional reflecting surface obtained by rotating the lower surface of the horizontal resonator vertical emission type LD by 45 degrees is further rotated by θ degrees to obtain a surface of 45 + θ degrees. At this time, the light reaching the exit surface has an angle of 2θ with respect to the vertical direction. Furthermore, since there is a difference in refractive index between the horizontal resonator vertical emission type LD 100 and air, the angle of emission is further increased according to Snell's law. Sinφ / n0 = Sin2θ / n1 is established, where φ is the outgoing angle, n0 is the refractive index of air, and n1 is the refractive index of the semiconductor LD. The refractive index of a normal semiconductor LD is as large as about 2.5 to 3.5, and φ can be increased even if θ is a small angle. φ is an incident angle of the laser beam to the upper surface of the slider 110.

FIG. 3 is an example of calculation of the return rate of reflected light when the mirror angle is shifted from 45 degrees by θ degrees. The calculation conditions were 780 nm, which is the wavelength of a widely used semiconductor LD, and a Gaussian with a light spot size having a radius of 2 μm in the horizontal direction and 1 μm in the vertical direction. The graph shows the θ dependence of the ratio of the feedback rate into the LD when compared with the case where light is incident on the reflecting surface perpendicularly (φ = 0, θ = 0). When θ = 1 degree, the feedback rate is about 50% when θ = 0.

A film for controlling the reflectance is formed on the light exit surface of the normal FP type LD so that the reflectance is about 5%, for example, 5% is fed back to the active layer inside the FP type LD, The remaining 95 percent is taken out as emitted light.

Of the light reflected by the light exit surface, when θ = 1 degree, the feedback rate to the active layer of the LD is 2.5% because it is 0.5 times 5%. If the reflectivity of the light output surface is made 10%, which is twice the reflectivity of the control film so as to return this to 5%, the feedback rate of the LD to the active layer is 5%, and the ratio of taking out as output light is 90%. Become a percentage. A loss of 5 percent is reflected by the exit surface and does not return. The ratio of taking out as outgoing light to the outside is 0.947 times as compared with the case of θ = 0, but the reduction amount is slight. That is, it can be seen that if θ = 1 ° or less, the effect on the light emission characteristics is not a problem in practice.

Next, a distributed feedback type (DFB type) LD was used. Since the DFB type LD is structured to reflect by a diffraction grating of the resonator, the reflectance of the exit surface is made substantially zero. Therefore, a reduction in feedback rate due to θ was not a problem.

Next, the effect of tilting the emission direction by θ will be described. The laser beam 203 emitted from the horizontal resonator vertical emission type LD 100 reaches the upper surface of the slider 110 and is incident obliquely at an incident angle φ. At this time, as φ is larger, the light reflected on the surface of the slider 110 is not fed back to the horizontal resonator vertical emission LD 100, and the return light becomes smaller. Although θ and φ are proportional to each other according to Snell's law, the semiconductor constituting the horizontal resonator vertical emission type LD 100 has a large refractive index. Therefore, even if θ is very small, φ is relatively large. FIG. 4 shows the relationship between θ and φ when n0 = 1 and n1 = 3. For example, when θ = 1 degree, according to the Snell's law equation, φ = 6 degrees. As a result, a large φ can be obtained with a small θ, so that the angle of the emitted light can be greatly tilted with respect to the vertical direction without substantially degrading the characteristics of the vertical resonator horizontal emission type LD. Can be suppressed.

In this embodiment, the reflectance suppression film 119 is formed on the upper surface of the slider 110 to further suppress the reflectance and suppress the generation of the reflected return light 212. The reflectivity suppressing film 119 is difficult to make the reflectivity completely zero with respect to the wavelength range changing with temperature, but has a certain effect on lowering the reflectivity in a certain wavelength range, so it is attached with φ. In combination with this, the effect increases.

Next, the obliquely incident light propagates through the optical waveguide 111-1 passing through the slider 110 and reaches the ABS. In this embodiment, the optical waveguide 111-1 has an angle in the light reflection direction at the ABS by inclining the waveguide from the normal direction of the ABS. Therefore, the reflected return light at the ABS can be suppressed. Further, the distance between the recording medium and the slider 110 and the flying posture of the slider 110 dynamically change when the slider 110 floats on the rotating recording medium (disk), but the light that is emitted from the ABS and reaches the recording medium. Since the incident angle can be obtained, it is considered that reflected return light from the recording medium is also relatively suppressed.

Further, a near-field light generating element for generating a minute light spot is formed in the vicinity of the optical waveguide 111-1 in the vicinity of the ABS of the optical waveguide 111-1.

In addition, when light transmitted without leaking from the ABS or leaked light is emitted from the ABS, there is return light 214 reflected on the disk surface. This is also because the optical waveguide 111-1 is angled. Since the optical axis of the return light is deviated from the optical waveguide 111-1, the amount of the return light is reduced.

Further, the reflected return light can be reduced by obliquely making the light incident on the upper surface of the slider 110, but the optical waveguide 111 provided so as to penetrate the slider 110 extends in the vertical direction as shown in FIG. The coupling efficiency with the optical waveguide 111 may be reduced. In this embodiment, the position of the optical waveguide 111 is shifted in the same direction as the incident light is inclined, and the inclination direction is also shifted, so that the light coupling efficiency on the upper surface of the slider 110 which is the incident surface is improved. improves.

Next, a method for manufacturing such an inclined optical waveguide 111-1 in the slider 110 will be briefly described.

The slider 110 is laminated by a wafer process with the left side (inflow end) in FIG. 2 facing down and the right side (outflow end) in FIG. 2 facing up. After laminating by the wafer process, cutting is performed so that the direction of the optical waveguide is oblique by dicing, or an angle is given by polishing after dicing. As a result, the slider 110 formed by this process has a laminated structure substantially parallel to the optical waveguide 111-1 (parallelism at the level of in-plane flatness of the film). By adopting such a structure, it is a simple process that increases the number of processes by dicing so as to be inclined or angled by polishing, and it is relatively easy without greatly changing the conventional wafer process. The slider 110 in which the optical waveguide is inclined with respect to the normal line of the upper and lower surfaces of the slider can be manufactured.

As described above, the conventional optical waveguide structure having the reflective surface shifted from the taper angle can suppress the reflected return light by tilting the slider optical path without changing the basic mounting method. it can.

In addition, the present reflecting surface can provide a great effect in the horizontal resonator vertical emission type LD in which the reflecting mirrors are integrated. However, the reflecting surface is not a horizontal resonator vertical emission type LD, that is, an optical waveguide with gain in which the reflecting mirrors are integrated. Even if a passive optical waveguide (semiconductor optical waveguide or organic optical waveguide) with a large refractive index integrated with sapphire is used, the return angle can be reflected without changing the mounting form (surface mounting) by changing the angle of the mirror in the same way. The effect of suppressing light is obtained.

FIG. 6 is a schematic cross-sectional view of the vicinity of the heat-assisted magnetic recording head of the magnetic disk device, showing a cross section at the center in the direction perpendicular to the ABS in the direction from the inflow end (left in the figure) to the outflow end (right in the figure). is there.

The surface close to the active layer 101 of the horizontal resonator vertical emission type LD 100 is connected to the bottom surface of the recess of the submount 150 via a solder 109. The upper portion of the submount 150 is connected to the gimbal (or flexure) 122 and supported by the suspension 121. The lower surface of the submount 150 is connected to the slider 110, the horizontal resonator vertical emission type LD 100 is a Fabry-Perot laser, and the resonator direction parallel to the active layer 101 is parallel to the ABS of the slider 110. Implemented sideways.

Here, the reflecting surface 104 of the horizontal resonator vertical emission type LD 100 used for the thermally-assisted magnetic recording head is centered on a line intersecting the lower surface of the horizontal resonator vertical emission type LD and the surface normal to the resonance direction. Thus, the conventional reflecting surface obtained by rotating the lower surface of the horizontal resonator vertical emission type LD by 45 degrees is further rotated by 1 degree to obtain a surface of 45 + 1 degrees.

One feature of this embodiment is the angle of this reflecting surface. This angle indicates that the reflection surface of the horizontal resonator vertical emission type LD used in the thermally assisted magnetic recording head intersects the laminated surface of the semiconductor layer constituting the horizontal resonator vertical emission type LD and the surface whose normal is the resonance direction. The laminated surface is rotated by 45 + θ (the absolute value of θ <45, θ ≠ 0) degrees or 135 + θ (the absolute value of θ <45, θ ≠ 0) degrees with the line to be rotated as an axis. That is, an XY plane having (X, Y, Z) = (0, 0, n) as a normal line is defined as a stacked surface of the semiconductor layers constituting the horizontal resonator vertical emission type LD, and the resonance direction is defined as (X, Y , Z) = (l, 0, 0), “(X, Y, Z) = (l, 0, n) or (−1, 0, −n)” and “l ≠ n” The reflecting surface is constituted by a surface having a normal line. In this way, the return light is suppressed by using a reflection surface that is deviated from the conventional θ = 45 degrees and 135 degrees.

An opening is provided in the bottom surface of the submount 150, and the emitted light of the horizontal resonator vertical emission type LD100 reaches the upper surface of the slider 110 through the opening.

In the slider 110, an optical waveguide 111-1 having an optical axis in the thickness direction is formed. The obliquely incident light propagates through the optical waveguide 111-1 passing through the slider 110 and reaches the ABS.

In this embodiment, the optical waveguide 111-1 has an angle in the light reflection direction at the ABS by inclining the waveguide from the normal direction of the ABS. Therefore, reflected return light at the ABS can be suppressed.

Further, the distance between the recording medium and the slider 110 and the flying posture of the slider 110 dynamically change when the slider 110 floats on the rotating recording medium (disk), but the light that is emitted from the ABS and reaches the recording medium. Since the incident angle can be obtained, it is considered that reflected return light from the recording medium is also relatively suppressed.

In addition, when light that has been transmitted without being absorbed from the ABS or leaked light is emitted from the ABS, there is return light that is reflected on the disk surface. This is also because the optical waveguide 111-1 is angled. Since the optical axis of the return light is deviated from the optical waveguide 111-1, the return light can be suppressed.

The reflected return light can be reduced by making the light incident obliquely on the upper surface of the slider 110, but the optical waveguide 111 provided so as to penetrate the slider 110 extends in the vertical direction as shown in FIG. The coupling efficiency with the optical waveguide 111 may be reduced. In this embodiment, the light incident on the slider is slanted and the position is also shifted from the emission position of the horizontal resonator vertical emission type LD. Therefore, the position of the optical waveguide 111 shown in FIG. First, the position of the upper end surface of the optical waveguide is shifted by the amount by which the position where the incident light hits the slider upper surface is shifted from directly under the output position of the output LD, and the optical waveguide is also inclined in the direction in which the incident light is inclined, By making the end surface of the optical waveguide on the upper surface of the slider an oblique cut surface of the optical waveguide, the light coupling efficiency on the upper surface of the slider 110, which is the incident surface of the optical waveguide 111-1, is improved.

Near the optical waveguide 111-1, there are a magnetic pole 112 for recording, a coil 113, and a magnetoresistive sensor 114 for generating a magnetic field. There is a near-field light generating element 115 near the ABS of the optical waveguide. There is a recording layer 132 in the vicinity of the surface of the recording medium 131, which absorbs the laser light to generate heat 222 and applies a recording magnetic field 221 for recording.

FIG. 7 is a schematic cross-sectional view of the vicinity of the thermally-assisted magnetic recording head of the magnetic disk device.

The difference from the first embodiment is that a passive optical waveguide 160 monolithically integrated with a reflecting mirror 164 is parallel to the ABS of the slider 110 in place of the horizontal resonator vertical emission type LD100. In this way, it is connected to the bottom surface of the concave portion of the submount 150 via an adhesive 159. The angle of the reflecting mirror 164 monolithically integrated in the optical waveguide is shifted from 45 degrees from the optical axis direction of the core. Even in this configuration, the reflection suppressing effect can be obtained as in the first embodiment.

FIG. 8 is a schematic cross-sectional view of the vicinity of a heat-assisted magnetic recording head of a novel magnetic disk device.

The difference from FIG. 6 is that the optical waveguide 111 of the slider 110 has a conventional slider structure.

That is, in this embodiment, the optical waveguide 111 employs a slider in which the optical waveguide extends in parallel to the normal direction of the ABS.

However, as in FIG. 6, the horizontal resonator vertical emission type LD 100 in which the reflection surface 104 is shifted from the conventional 45 degrees is used, so that there is a sufficient suppression effect on the return light on the surface of the slider 110.

FIG. 5 is a perspective view schematically showing a magnetic disk device using a heat-assisted magnetic recording head.

In the apparatus housing 400, the recording disk 402 is rotated by the spindle 403. The arm 405 is driven by a voice coil motor 401, and a suspension 406 is attached to the arm 405. Connected to the end of the suspension 406 is a thermally assisted magnetic recording head 410 in which the horizontal resonator vertical emission type LD 100 of any one of the first to third embodiments is mounted on the slider 110.

DESCRIPTION OF SYMBOLS 100 ... Horizontal resonator vertical emission type semiconductor LD element 101 ... which monolithically integrated the reflecting mirror ... LD active layer 102 ... LD n clad layer 103 ... LD p clad layer 104 ... horizontal Reflector 105 monolithically integrated in resonator vertical emission type LD ... Reflectivity control film 109 formed on the surface of horizontal resonator vertical emission type LD ... Solder 110 ... Slider 111 ... Slider 110 Optical waveguide 111-1 ... Optical waveguide 112 in the slider 110 inclined from the vertical direction ... Recording magnetic pole 113 ... Coil 114 ... Magnetoresistive sensor element 115 ... Near-field light generating element 119: Reflectance suppression film 120: Magnetic recording medium (magnetic disk)
121 ... Suspension 122 ... Gimbal (flexure)
131 ... Magnetic recording medium substrate 132 ... Recording layer 150 ... Optical waveguide 151 monolithically integrated with reflecting mirror ... Core layer 154 of optical waveguide ... Reflector 159 monolithically integrated with optical waveguide ..Adhesive 201... Laser beam 202 generated in LD... Laser beam 203 reflected by mirror monolithically integrated on LD... Laser beam 204 ... Laser beam 205 propagating through an optical waveguide in the slider 110 ... Laser beam 211 emitted from the lower surface (ABS) of the slider 110 and reaching the recording medium ... On the exit surface of the LD Reflected return light 212... Reflected return light 213 reflected on the upper surface of the slider 110... Reflected return light 214 reflected on the lower surface (ABS) of the slider 110. ... Reflected return light 221 reflected on the surface of the magnetic recording medium ... Recording magnetic field 222 ... Heat 300 ... Reflector mirror angle of 45 degrees with respect to the cavity direction of the LD 301 ... LD Reflector mirror angle 302 slightly deviated from 45 degrees with respect to the resonator direction .... Laser beam emission angle 303 from LD ... Laser beam incident angle 400 on slider 110 surface ... Recording disk device Case 401 ... Voice coil motor 402 ... Recording disk 403 ... Spindle 404 ... Signal processing LSI
405... Arm 406... Suspension 410... Thermally assisted magnetic recording head in which a horizontal resonator vertical emission type LD is mounted on the slider 110

Claims (10)

In a thermally assisted magnetic recording head comprising a slider and a first optical waveguide and a reflecting mirror mounted on the slider,
The slider includes a second optical waveguide that propagates from a first main surface on which the reflecting mirror is mounted to an opposite second main surface,
The first optical waveguide and the second optical waveguide are arranged at a position where they are optically coupled via the reflecting mirror,
The heat-assisted magnetic recording head according to claim 1, wherein an angle formed between a normal line of the reflecting surface of the reflecting mirror and the extending direction of the first optical waveguide is deviated from 45 degrees. In claim 1,
The heat-assisted magnetic recording head, wherein the first optical waveguide includes a gain region. In claim 2,
The reflecting mirror is monolithically integrated in the first optical waveguide,
The heat-assisted magnetic recording head according to claim 1, wherein the reflecting mirror and the first optical waveguide constitute a horizontal resonator vertical emission type semiconductor laser. In claim 1,
The first optical waveguide and the reflecting mirror are mounted on a submount,
The submount is mounted on the slider;
The submount includes an opening;
The thermally-assisted magnetic recording head, wherein the reflecting mirror and the second optical waveguide of the slider are optically coupled through the opening of the submount. In claim 4,
With gimbal or flexure,
The submount includes an upwardly recessed recess having the opening;
The lower surface of the recess is mounted on the slider,
The first optical waveguide and the reflecting mirror are mounted in the recess,
A heat-assisted magnetic recording head, wherein an upper surface of the recess is connected to the gimbal or flexure. In claim 1,
A heat-assisted magnetic recording head, wherein an angle formed by a reflecting surface of the reflecting mirror and a bottom surface of the first optical waveguide is deviated from 45 degrees within ± 1 degree. A slider having an optical waveguide connecting the first main surface and the second main surface,
The optical waveguide is shifted from the normal direction of the first main surface by a predetermined angle,
A pair of opposing side surfaces of the slider are also shifted by a predetermined angle from the normal direction of the first main surface. In claim 7,
The optical waveguide is provided with a thin film for reducing reflectance on the end surface thereof. In claim 1,
The second optical waveguide is shifted from the normal direction of the first main surface by a predetermined angle;
The heat-assisted magnetic recording head according to claim 1, wherein a pair of opposing side surfaces of the slider are also shifted by a predetermined angle from a normal direction of the first main surface. In claim 9,
The heat-assisted magnetic recording head, wherein the second optical waveguide is provided with a thin film for reducing reflectance on an end surface thereof.

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