JP2765552B2 - Wiring structure of optical bistable element array - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring structure of an optical bistable semiconductor laser applied to an optical memory device and the like, and more particularly, to a wiring structure of an optical bistable element array in which a plurality of optical bistable semiconductor lasers are integrated into one chip. About.

[0002]

2. Description of the Related Art An optical bistable semiconductor laser has a Fabry-probe resonator structure and generally has a sectional structure as shown in FIG. Referring to FIG. 4, the optical bistable semiconductor laser 41 includes an active layer 42, a cladding layer 43, half mirrors 44 and 45, and external extraction electrodes 46 and 47 divided into two in the longitudinal direction of the active layer 42. And a ground electrode 48.

[0003] The two external extraction electrodes 46, 4
By controlling the injection current into 7 and the intensity of the light input to the active layer 42, optical bistability occurs for the electrical or optical signal.

FIG. 5 is a graph showing the relationship between light input intensity and light output intensity for explaining the bistability. When the light input intensity is increased while the currents to be injected into the external extraction electrodes 46 and 47 of the optical bistable semiconductor laser 41 are kept constant, strong laser light is rapidly emitted at a predetermined threshold value. Also,
When the light input intensity decreases, the intensity sharply decreases below the threshold value. Optical bistability is made possible by this hysteresis of light output intensity.

The optical bistability can be applied to an optical memory function, but a large number of optical bistable semiconductor lasers are required to realize the optical memory function. In order to reduce the size of the device, integration of an optical bistable semiconductor laser is required.

FIG. 6 shows an array structure of a conventional optical bistable semiconductor laser proposed to cope with this miniaturization (for example, see a conventional example of Japanese Patent Application Laid-Open No. 1-192185). FIG. 6 shows an optical bistable element array 6 in which a plurality of optical bistable semiconductor lasers 41 shown in FIG.
1 is shown.

The optical bistable element array 61 is arranged so that the active layers 62 are parallel to each other (four in FIG. 6), and external extraction electrodes 63 and 64 for controlling each active layer are formed on the upper surface.
And a ground electrode 65 is formed on the bottom surface to form a one-chip array.

Usually, such an optical bistable element array 61
In the case of (1), the method of light input and light output is performed by an optical guide array (not shown) using an optical fiber, an optical waveguide, or the like.

In the optical bistable element array 61, as shown in FIG. 7, an external wiring electrode 71 such as a package and the external extraction electrodes 63 and 64 of the optical bistable element array 61 are wired by bonding wires 72. Be composed.

[0010]

However, in the case of the wiring structure shown in FIG. 7, the length of the bonding wires becomes longer and the bonding wires 72 may intersect.
As a result, when employed in an optical memory device or the like that performs high-speed signal processing, it may cause noise such as crosstalk. This is due to the parasitic capacitance component of the bonding wire 72. Particularly, the higher the speed, the more remarkable noise occurs.

Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to reduce a parasitic capacitance component of a bonding wire, improve a frequency characteristic, and cope with a high-speed signal processing device. It is to provide a wiring structure.

[0012]

In order to achieve the above object, the present invention provides an optical bistable element array in which a plurality of optical bistable semiconductor lasers are formed into a one-chip array and an external extraction electrode is formed on an upper surface. A light guide array arranged on the input light side and the output light side of the optical bistable element array to guide laser light, and on the upper surface of the optical guide array, the optical bistable element array Forming an external wiring electrode at a position close to the external extraction electrode, and connecting the external extraction electrode of the optical bistable element array and the external wiring electrode of the optical guide array with a bonding wire; Provided is a wiring structure of an element array.

According to the present invention, the external wiring electrodes are formed on the upper surface of the optical guide array, and are arranged close to the external extraction electrodes of the optical bistable element array, so that the bonding wire length can be shortened and a plurality of external wiring electrodes can be formed. This eliminates intersections between bonding wires and enables high-speed signal processing.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a wiring structure of an optical bistable element array according to one embodiment of the present invention. Referring to FIG. 1, on an upper surface of an optical bistable element array 11, an external extraction electrode 12,
13. An optical guide array 1 comprising optical fibers 14 on the input light side and output light side of the optical bistable element array 11.
5 and external wiring electrodes 17 and 18 are provided on the upper surface of the cover 16 of the light guide array 15, and the external extraction electrode 1 is provided.
2A and 2B are formed at positions close to each other and are electrically connected by bonding wires 19.

FIGS. 2 and 3 are exploded perspective views for explaining the structure of the light guide array 15 in detail. The light guide array 15 includes a V-groove substrate 32 formed by forming a V-groove 31 on a silicon substrate by anisotropic etching, an optical fiber 14, and a cover 16. The mutual pitch of the V-grooves 31 is the same as the pitch of the active layer of the optical bistable element array 11, and the depth direction of the V-groove 31 is the center line of the optical fiber 14 mounted on the V-groove 31 and the optical bistable element array. The height of the active layer 11 coincides with that of the active layer. Also, V
A mounting portion (groove) 33 for the optical bistable element array 11 is formed in the center of the groove substrate 32.

The cover 16 is preferably made of a ceramic or glass substrate, and has an optical bistable element array 11 on the surface.
External wiring electrodes 17 and 18 are formed at positions close to the external extraction electrodes 12 and 13 by metal deposition or the like.

The optical fiber 14 has a non-reflective coating on the end face of the front end lens or the like.

The V-groove substrate 32 processed by the above method
, The optical fiber 14 and the cover 16, the optical bistable element array 11 is mounted at the center position of the V-groove substrate 32 by bonding or the like, and then the optical fibers 14 are mounted in the respective V-grooves 31. The light guide array 15 is formed by bonding and fixing at 16.

[0020]

As described above, according to the present invention,
External wiring electrodes are formed on the upper surface of the cover of the optical guide array at positions close to the external extraction electrodes of the optical bistable element array, so that the bonding wire length can be shortened, and there is no intersection between bonding wires. Therefore, the present invention provides a wiring structure of an optical bistable element array suitable for an optical memory device requiring high-speed signal processing.

[Brief description of the drawings]

FIG. 1 is a diagram showing a wiring configuration according to an embodiment of the present invention.

FIG. 2 is an exploded view of a light guide array for describing one embodiment of the present invention, and is a perspective view of a cover.

FIG. 3 is an exploded view of a light guide array for describing one embodiment of the present invention, and is a perspective view of a silicon V-groove substrate.

FIG. 4 is a sectional view of an optical bistable semiconductor laser.

FIG. 5 is a diagram for explaining optical bistability, and is a graph showing a relationship between light input intensity and light output intensity.

FIG. 6 is a perspective view showing a configuration of a conventional optical bistable element array in which a plurality of optical bistable semiconductor lasers are formed into a one-chip array.

FIG. 7 is a diagram showing a conventional wiring structure of an optical bistable element array.

[Explanation of symbols]

 Reference Signs List 11 optical bistable element array 12, 13 external extraction electrode 14 optical fiber 15 optical guide array 16 cover 17 external wiring electrode 18 external wiring electrode 19 bonding wire 31 V groove 32 V groove substrate 33 mounting location 41 optical bistable semiconductor laser 42 active Layer 43 Cladding layer 44, 45 Half mirror 46 External extraction electrode 47 External extraction electrode 48 Ground electrode 61 Optical bistable element array 62 Active layer 63 External extraction electrode 64 External extraction electrode 65 Ground electrode 71 External wiring electrode 72 Bonding wire

Claims (3)

(57) [Claims] 1. An optical bistable element array in which a plurality of optical bistable semiconductor lasers are formed into a one-chip array and an external extraction electrode is formed on the upper surface, and an input light side and an output light side of the optical bistable element array. A light guide array that guides laser light by arranging them in each,
In the wiring structure, an external wiring electrode is formed on the upper surface of the optical guide array at a position close to the external extraction electrode of the optical bistable element array, and the external extraction electrode of the optical bistable element array and the optical guide array are formed. Wherein the external wiring electrodes are connected by bonding wires. 2. The optical bistable element according to claim 2, wherein a plurality of external wiring electrodes of the optical guide array are arranged along a longitudinal direction of the optical bistable element array, and each of the plurality of external wiring electrodes respectively corresponds to the optical bistable element. 2. The wiring structure of an optical bistable element array according to claim 1, wherein the wiring structure is arranged close to an external extraction electrode of the array. 3. The wiring structure of an optical bistable element array according to claim 1, wherein external wiring electrodes of said optical guide array are formed on a cover surface of said optical guide array.