JP2002214484A - Optical element module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize compactness and high integration. SOLUTION: On the surface of a silicon substrate 21, by anisotropic etching, a square recessed part 22 is formed and V grooves 23 and 24 are formed on one side with respect to the part 22 on two straight lines passing through the center of the square. A spherical lens 27 is arranged in the part 22, and optical fibers 28 and 29 are arranged respectively in the grooves 23 and 24. Optical elements (LD, PD) 31 and 33 are arranged at positions opposing the fibers 28 and 29 across a spherical lens 27 on the substrate 21. The single spherical lens 27 is shared by two sets of modules (the optical elements and the optical fibers).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element module used for an optical communication or optical measurement device, and more particularly to an optical element module which can be miniaturized and highly integrated.

[0002]

2. Description of the Related Art In an optical element module for connecting an optical element such as a light-emitting element or a light-receiving element to an optical fiber, it is generally necessary to connect one set of optical element and the optical fiber in one optical element module. For example, in an optical element module that connects a light emitting element and an optical fiber, a lens is disposed between the light emitting element and the optical fiber to increase the optical coupling efficiency, and the lens is There is also adopted a configuration in which the connection is made via a connection.

FIG. 2 shows an example of a conventional configuration of such an optical element module.
The light emitted from D) 11 is condensed on the core portion of the optical fiber 13 by the spherical lens 12 and is incident thereon, whereby high coupling efficiency (connection efficiency) is obtained. As shown in the figure, such an LD module is often provided with a photodiode (PD) 14 for normal light emission amount monitoring. The mounting substrate 15 is, for example, a silicon substrate, and the optical elements (LD, PD) 11 and 14 are aligned with the alignment marks 16 formed with high precision.
The ball lens 12 and the optical fiber 13 are solder-fixed on the electrode 17 formed thereon, while the spherical lens 12 and the optical fiber 13 are formed by anisotropic etching of silicon and have a highly accurate rectangular recess 18.
In addition, they are arranged in the V-groove 19 and are fixed by bonding, thereby realizing high coupling efficiency by passive alignment. In the drawing, reference numeral 20 denotes a bonding wire.

[0004]

As described above, in the conventional optical element module, the connection between the optical element such as the light emitting element and the light receiving element and the optical fiber is basically one set for each optical element module. Even if a plurality of sets of optical elements and optical fibers are integrated in one package, each set, that is, a plurality of independent sets is simply mounted. In view of the above, an object of the present invention is to provide an optical element module including a plurality of sets of optical elements and optical fibers, which can achieve higher integration than the conventional configuration. .

[0005]

According to the first aspect of the present invention, the optical element and the optical fiber are arranged on two straight lines passing through the center of the spherical lens with the spherical lens interposed therebetween.
According to the second aspect of the present invention, a rectangular recess and a V-groove are formed on one side of the rectangular recess on two straight lines passing through the center of the square by anisotropic etching on the surface of the silicon substrate. , A spherical lens is arranged in the rectangular recess,
Optical fibers are respectively arranged in the two V-grooves, and optical elements are respectively arranged on the silicon substrate at positions facing the respective optical fibers with the spherical lens interposed therebetween.

[0006]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows the configuration of an embodiment of an optical element module according to the present invention. In this example, one spherical lens is shared by a plurality of pairs of an optical element and an optical fiber. The rectangular substrate 21 is a silicon substrate, and a rectangular concave portion 22 and two V grooves 23 and 24 are formed on the surface thereof. V
The grooves 23 and 24 are formed on one side of the recess 22 on two straight lines passing through the center of the rectangle formed by the recess 22. In this example, the grooves 23 and 24 are perpendicular to two adjacent sides of the recess 22 as shown in the drawing. And the inner ends thereof are respectively formed with recesses 2.
It is supposed to face 2.

The V-grooves 23, 24 and the concave portion 22 are formed into required dimensions with sub-micron level dimensional accuracy by high-precision pattern formation by photolithography and anisotropic etching of silicon. . On the other hand, a required electrode 25 and a cross-shaped alignment mark 26 are formed on the substrate 21 in the vicinity of the side of the concave portion 22 opposite to the side where the V grooves 23 and 24 are formed. The electrode 25 and the alignment mark 26 are also formed by photolithography in the concave portion 22 and the V-groove 2.
It is formed with a high positional accuracy of 3, 24, and has an excellent shape accuracy. Note that gold-tin solder including the thickness is formed on the electrode 25 with high accuracy.

A spherical lens 27 and optical fibers 28 and 29 are arranged in the concave portion 22 and the V-grooves 23 and 24, respectively, and are adhered and fixed. On the other hand, an LD 31 and a monitor PD 32 for monitoring the amount of emitted light thereof are arranged at a position facing the optical fiber 28 with the spherical lens 27 interposed therebetween, and a PD 33 is arranged at a position facing the optical fiber 29 with the spherical lens 27 interposed therebetween. You. These LD31, monitor PD32 and PD33
Are aligned by the alignment marks 26 and fixed on the electrodes 25 by soldering, and required electrical connections are made by bonding wires 34.

In the above configuration, the optical fiber 2
8, 29 and eccentricity of ball lens 27, LD 31, monitor P
By using D32 and PD33 light emitting / receiving points having a submicron level deviation and mounting them at predetermined positions, a high-precision passive alignment required for the entire optical element module is realized. According to the optical element module shown in FIG. 1, the optical fiber 28, the ball lens 27, the LD 31, the monitor PD 32 and the substrate 21, the electrode 25, the gold tin solder, and the bonding wire 3 attached thereto are provided.
4 functions as a set of LD modules, and similarly, the optical fiber 29, the spherical lens 27, the PD 33, and the substrate 21, the electrodes 25, the gold tin solder, and the bonding wires 34 attached thereto function as a set of PD modules.

In other words, according to this example, one set of high coupling efficiency LD modules and one set of high coupling efficiency PD modules share one ball lens, so that two sets of module functions are integrated into one set. It is integrated in a module form. In this example, each optical element of the two modules is an LD and a PD, that is, a light emitting element and a light receiving element. However, the present invention is not limited to this. For example, each optical element of the two modules is a light receiving element. May be
Both may be light emitting elements.

[0011]

As described above, according to the present invention, since one ball lens is shared by two sets of optical elements and optical fibers, a compact, high-integration, high-performance device having two module functions is provided. An optical element module with low coupling efficiency and low cost can be realized. In addition, a silicon substrate is used as a mounting substrate, and a concave portion for mounting a spherical lens and two V-grooves for mounting an optical fiber are formed by anisotropic etching, so that two sets of modules can be formed on a single substrate with high precision. And it can be easily configured.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a plan view showing a conventional optical element module.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 31/02 D

Claims (2)

[Claims] 1. An optical element module, wherein an optical element and an optical fiber are arranged on two straight lines passing through the center of a spherical lens with the spherical lens interposed therebetween. 2. The method according to claim 1, wherein a V-groove is formed on the surface of the silicon substrate by anisotropic etching, and a V-shaped groove is formed on one side of each of the rectangular recesses on two straight lines passing through the center of the rectangular recess. A spherical lens is arranged in the concave portion, an optical fiber is arranged in each of the two V-grooves, and an optical element is arranged on the silicon substrate at a position facing each optical fiber with the spherical lens interposed therebetween. Characteristic optical element module.