JPH10302296A - Optical integrated head module - Google Patents

Abstract

(57) Abstract: relates to an optical integrated head module, when constituting an optical integrated head module with S ³ laser, without requiring a complicated structure and method, the direction of polarization and a normal laser Similarly, correct horizontally. SOLUTION: An Si substrate 31 in which a light receiving section 35 is formed.
A micro-prism 32 having a rising mirror 32A having an inclined surface on which polarized light is incident, a light emitting region in which the polarization of emitted light is inclined with respect to the surface to be bonded, and viewed in a plane. An S ³ laser fixed at a position where polarized light is incident on the rising mirror 32A at an angle that compensates for the inclination of the polarized light is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a small and inexpensive optical integrated head module suitable for use in a large-capacity external storage device such as a magneto-optical disk device.

At present, an optical integrated head module is a CD.
(Compact disk) devices and DVDs (digital
tal video disk) device, etc.
In addition, a magneto-optical disk (magneto-optical)
l disk) devices.

By appropriately selecting a certain semiconductor laser as a light source of such an optical integrated head module, that is, a plane index and an impurity in a crystal growth surface, a p-type light-emitting region having a stripe in an active layer and This problem is solved because it is difficult to use an S ³ laser in which n-type current block regions located on both sides thereof are automatically generated (see Japanese Patent Application Laid-Open No. 6-45708 if necessary). Need
According to the present invention, one means for responding to this can be provided.

[0004]

2. Description of the Related Art FIG. 3 is a perspective view of an essential part showing an optical integrated head module developed for a disk such as a CD, and a chip is shown in an enlarged manner in a box in the upper right of the figure.

In the figure, 1 is a comb type resin hollow package, 2 is a chip in which a semiconductor laser, a light receiving element and a mirror are integrated, 2A is a recess, 3A is a semiconductor laser
A chip 3B is a light receiving element, 3C is a mirror, and 4 is a hologram optical element.

In this optical integrated head module, a recess 2A is formed in a chip 2 made of Si, and an AlGaAs-based semiconductor laser chip 3A emitting light at a wavelength of, for example, 780 [nm] is bonded therein. A 45 ° mirror 3C is formed on the surface facing the light emitted from the laser chip 3A so that the light emitted from the semiconductor laser chip 3A rises vertically.

The vertically emitted light is incident on a disk such as a CD, and the light reflected by the disk is
The light is incident on the light receiving elements 3B disposed on both sides of the recess 2A and returns.

[0008]

In the optical integrated head module described with reference to FIG. 3, the light source AlGa is used.
As-based semiconductor laser chip 3A is made of AlGaInAsP
By replacing the high-power red semiconductor laser with a system, it is possible to apply it to a large-capacity magneto-optical disk device such as 640 [MB]. The direction of polarization is particularly important because the signal is read by the method.

By the way, A for the magneto-optical disk drive
As a 1GaInAsP high-output red semiconductor laser,
S ³ (self-aligned) disclosed in the above document
Stepped substrate lasers have very good properties.

[0010] FIG. 4 is a partial sectional front view showing an S ³ laser is AlGaInAsP-based high-power red semiconductor laser.

In the figure, 11 is a substrate, 12 is a cladding layer, 13 is a strained MQW active layer, 13A is a p-type light emitting region,
13B is an n-type region, 14 is a first cladding layer, 15 is a current blocking layer, 16 is a second cladding layer, and 17 is a contact layer.

The main data relating to each of the illustrated semiconductor parts is as follows. Substrate 11 Material: n-GaAs Plane index of main surface: (100) 6 ° off Plane index of slope: (411) A Cladding layer 12 Material: n-AlGaInP Strained MQW active layer 13 Material: GaInAsP / AlGaInP First cladding layer 14 Material: p-AlGaInP Current blocking layer 15 Material: n-AlGaInP Second cladding layer 16 Material: p-AlGaInP Contact layer 17 Material: p-GaAs

The S ³ laser has a principal surface having a plane index of (100).
By selectively etching the substrate 11 which is 6 ° off, (411) A
When the strained MQW active layer 13 is formed by using a stepped substrate having an exposed surface, a p-type impurity and an n-type impurity whose incorporation rate into the semiconductor crystal largely depends on the plane orientation, for example, Zn
And Se are co-doped, and (411) A surface has p
A pattern light emitting region 13A and an n-type region 13B on the (100) ° off plane are automatically generated to have a current blocking function.

As described above, the S ³ laser has a great feature that a real refractive index waveguide type semiconductor laser having excellent beam characteristics such as astigmatism and aspect ratio can be easily realized by one crystal growth. is there.

However, as is apparent from the figure, S ³
The polarized light from the light emitting region 13A in the laser is not parallel to the upper and lower surfaces of the chip as in a normal laser, but is 13.5.
° is inclined.

[0016] Therefore, when used as a light source for optical integrated head module seen the S ³ laser 3, polarized light emitted when is confronting the S ³ laser and the mirror 3C from S ³ laser horizontal mirror 3C Therefore, the light reflected by the mirror 3C cannot rise while maintaining a desired angle, and cannot exchange signals with the medium.

In order to cope with such a situation, it is necessary to redesign the optical system exclusively for the S ³ laser, and in that case, the cost is unavoidable.

According to the present invention, when constructing an optical integrated head module using an S ³ laser, the direction of polarization is corrected horizontally as in a normal laser, without requiring a complicated configuration or method.

[0019]

In the present invention, there is provided a means for solving], according to the inclination of the in polarization to S ³ laser, the arrangement angle of the S ³ laser to be incident obliquely to mirror up light in a plan view By compensating for the tilt of the polarization,
The principle is to make the light incident on the rising mirror horizontal.

FIG. 1 is an explanatory diagram showing a positional relationship between light and a micro prism for explaining the principle of the present invention.

As shown in FIG. 2A, when a horizontal polarized light 22 is vertically incident on a micro prism 21 having a rising mirror 21A having a tilt angle of 45.degree. In addition, the polarization direction of the emitted light 22A does not change.

Also, the polarized light 22 described in (A)
As shown in (B), the polarization direction of the emitted light 22A on the rising mirror 21A and the rising direction of the emitted light 22A is constant irrespective of the angle of incidence seen in a plane.

However, as shown in FIG. 3C, when the polarized light 22 whose polarization direction is perpendicular to the installation surface of the micro-prism 21 is incident on the rising mirror 21A, it depends on the angle of incidence seen on the plane. The polarization direction on the rising mirror 21A changes.

In other words, when the polarized light incident on the inclined rising mirror is other than horizontal, that is, when the polarized light is inclined with respect to the horizontal, the incident angle of the light incident on the rising mirror as viewed in a plane is expressed by Accordingly, by appropriately selecting the angle to arrange the S ³ laser, can be polarized on the surface of the rising mirror is corrected so that the horizontal, in the present invention utilizes this principle.

From the above description, in the optical integrated head module according to the present invention, (1) a semiconductor light receiving element (for example, the light receiving portion 35) is formed on a substrate (for example, the Si substrate 31) on which the light receiving portion 35 is formed. A polarization rising mirror (for example, a micro-prism 32 having a rising mirror 32A) having an inclination on a plane on which polarized light is incident, and a light emitting area (for example, a p-type light emitting area) in which the polarization of emitted light is inclined with respect to the surface to be bonded. 13A: comprising a Figure 4) has and plane viewed the polarization raising semiconductor lasers which are fixed in a position to incident polarized light at an angle to compensate for the tilt of the mirror to the polarization (e.g. S ³ laser 34) Characterized in that, or

(2) In the above (1), the substrate on which the semiconductor light receiving element is formed is a silicon photodiode, or

(3) In the above (1) or (2),
The polarization raising mirror is characterized by being formed by etching the substrate, or

(4) In any one of the above (1) to (3), the semiconductor laser is a red semiconductor laser made of an AlGaInAsP-based material, and the angle for compensating for the polarization inclination is 13.5. ° ± 1 °.

By adopting the above-mentioned means, even if the polarization direction of the S ³ laser is inclined differently from the ordinary laser, the polarization can be changed by appropriately selecting the position of the S ³ laser with respect to the rising mirror. It is possible to adjust the angle of incidence on the rising mirror and correct the direction of polarization so that it is horizontal like a normal laser, and to achieve the correction, a complicated configuration or complicated Requires no special methods.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a perspective view showing a principal part of an optical integrated head module for explaining an embodiment of the present invention.

[0031] In the figure, the Si substrate 31, 32 is a micro-prism, 32A is in raising mirror in the micro-prism, 33 is a sub-mount, 34 S ³ laser, 35 is a light receiving portion, 36 around The axis 37 indicates the axis when the S ³ laser is disposed at an angle.

Here, the Si substrate 31 is represented by the light receiving portion 35, but a multi-divided Si photodiode is formed, and the micro prism 32 is formed of resin between the divided light receiving portions 35. It is fixed.

A submount 33 made of AlN to which an S ³ laser 34, which is an AlGaInAsP-based high-power red laser, is fixed with a solder material, is disposed to face the rising mirror 32 A of the microprism 32.

Although not shown, the entire structure described above is housed in a ceramic package or a resin package, and the package is covered with a metal or resin cap having a hologram optical element.

As is apparent from the drawing, in this optical integrated head module, the submount 33 on which the S ³ laser 34 is mounted is aligned with the axis 37 deflected by an angle a = 13.5 ° with respect to the central axis 36. Accordingly, the polarized light from the S ³ laser 34 is horizontal on the surface of the rising mirror 32A, and the polarization direction of the emitted light, which is the reflected light, is maintained in the same direction.

In the present invention, many other modifications can be realized without being limited to the above-described embodiment. For example, in the optical integrated head module, a micro prism is used for a rising mirror. , This is Figure 3
As described above, a mirror formed by etching a Si chip may be used.

[0037]

In the integrated optical head module according to the present invention, there is provided a polarized light rising mirror having an inclination on a plane on which polarized light is incident on a substrate on which a semiconductor light receiving element is formed.
A semiconductor laser having a light emitting region in which the polarization of the emitted light is inclined with respect to the surface to be bonded and fixed at a position where the polarized light is incident on the polarization rising mirror at an angle that compensates for the inclination of the polarized light when viewed in a plane ( S ³ laser).

By adopting the above configuration, even if the polarization direction of the S ³ laser is inclined differently from the ordinary laser, the polarization can be changed by appropriately selecting the position of the S ³ laser with respect to the rising mirror. It is possible to adjust the angle of incidence on the rising mirror and correct the direction of polarization so that it is horizontal like a normal laser, and to achieve the correction, a complicated configuration or complicated Requires no special methods.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a positional relationship between light and a micro prism for explaining the principle of the present invention.

FIG. 2 is a perspective view showing a main part of an optical integrated head module for explaining an embodiment of the present invention.

FIG. 3 is a perspective view of an essential part showing an optical integrated head module developed for a disk such as a CD.

4 is a main part sectional front view showing an S ³ laser is AlGaInAsP-based high-power red semiconductor laser.

[Explanation of symbols]

21 micro-prism 21A polarization raising mirror 22 polarizing 22A was launched emitted light 31 Si substrate 32 micro prism 32A in the raising mirror 33 submount micro prism 34 S ³ laser 35 light receiving portion 36 the central axis 37 S ⁽³ ) Axis when the laser installation position has an angle

Claims (4)

[Claims] 1. A polarization rising mirror having an inclination on a surface on which polarized light is incident on a substrate on which a semiconductor light receiving element is formed, and a light emitting region in which the polarization of emitted light is inclined with respect to a surface to be bonded. An optical integrated head module, comprising: a semiconductor laser fixed at a position where the polarized light is incident on the polarization rising mirror at an angle that compensates for the inclination of the polarized light when viewed in a plane. 2. The optical integrated head module according to claim 1, wherein the substrate on which the semiconductor light receiving element is formed is a silicon photodiode. 3. The optical integrated head module according to claim 1, wherein the polarization raising mirror is formed by etching a substrate. 4. The semiconductor laser according to claim 1, wherein the semiconductor laser is a red semiconductor laser made of an AlGaInAsP-based material, and an angle for compensating a tilt of polarization is 13.5 ° ± 1 °. An optical integrated head module according to any one of the above.