JPH02281219A - Light emitting element module - Google Patents

Abstract

PURPOSE:To prevent the drift of an optical axis caused by the insertion and drawing of a ferrule from occurring and to stabilize coupling efficiency by making light incident on an optical fiber which is held by the ferrule through an attenuation plate and coaxially coupling two ferrules with the aid of using a split sleeve. CONSTITUTION:When the attenuation plate 21 and a condensing lens 13 are arranged on one end face of the ferrule 14 where the short optical fiber 15 is held on the center axis and the other end face part of the ferrule 14 is inserted to the cylindrical split sleeve 16, the light from a semiconductor light emitting chip 11 is made incident on the optical fiber 15 through the condensing lens 13 and the attenuation plate 21. Besides, when the ferrule 19 of an optical connector having the same outside diameter as the ferrule 14 is inserted from the opposite side of the split sleeve 16, two ferrules are coaxially arranged with excellent reproducibility. Thus, the drift of the optical axis caused by the insertion and drawing of the ferrule hardly occurs and the coupling efficiency of the light is stabilized. Besides, the quantity of the light can be optionally adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a light emitting element module used as a light source for optical communication/optical measurement.

2. Description of the Related Art Conventionally, this type of light emitting element module has had a structure as shown in FIG. In FIG. 4, 1 is a semiconductor light emitting chip, 2 is a stem to which the light emitting chip 1 is fixed, 3 is a rod lens, 4 and 6 are first and second housings, respectively, and 6 is an optical connector that holds an optical fiber 7. 7 errules in the second housing 5. A hole 8 is provided for inserting the light emitting chip 1, and after the light emitted from the light emitting chip 1 is focused by the rod lens 3, the ferrule body 4
and the second housing 5 are fixed to each other.

3.\-7 As described above, conventionally, a receptacle-type light-emitting module has been constructed in which the optical connector FEL-V6 can be inserted and removed.

Problems to be Solved by the Invention In such a conventional configuration, backlash occurs due to the dimensional difference between the inner diameter of the hole 8 of the second casing 6 and the outer diameter of the ferrule 6, and especially when the core diameter When using a small single-mode optical fiber, there is a drawback that the amount of light incident on the optical fiber 7, that is, the coupling efficiency, changes greatly due to the insertion and removal of the optical connector fiber (V-)V6.

The present invention solves these problems.

The object of the present invention is to provide a receptacle-type light emitting element module in which optical axis deviation caused by insertion and removal of a ferrule to which an optical fiber is fixed is small and coupling efficiency is stable.

Means for Solving the Problem In order to solve this problem, the present invention provides a ferrule that holds a short optical fiber on the central axis and has a ferrule with both end surfaces polished. Arrange the plate and condensing lens, insert the other end part halfway into the cylindrical split sleeve, and let the light from the semiconductor light emitting chip enter the optical fiber of the ferrule via the lens and the light attenuation plate. It is configured as follows.

Effect of the Invention With the above-described configuration, the present invention allows light from the semiconductor light-emitting chip to enter a short optical fiber held on the central axis of the ferrule via the condenser lens and the light attenuation plate. Therefore, by inserting the ferrules from the opposite side of the cylindrical split sleeve, the two ferrules can be placed almost at the same height with good reproducibility, and the optical fibers fixed to the central axis of the 7 ferrules of the optical connector can be In addition to efficiently combining light, the amount of light can be adjusted to any desired level using a light attenuation plate.

Functions as an excellent light emitting element module.

Embodiment FIG. 1 is a sectional view showing the structure of a light emitting element module p according to an embodiment of the present invention. In the same figure.

11 is a semiconductor light emitting chip, 12 is a stem for fixing the light emitting chip 11, 13 is a rod lens, 14 is a cylindrical ferrule holding a short optical fiber 15 on its central axis, and 16 is a cylindrical split sleeve. , 17 and 18 are housings, 19 is a ferrule of an optical connector connected from the outside, holding an optical fiber 20 in the shape of a central axis, and 21 is a housing 1
This is a light attenuation plate that is detachably held in the groove 22 of No. 7 and attenuates the amount of light and allows it to pass through.

The stem 12 and the ferrule/L/14 are fixed to the housing 17. FEL-/l/14 has both end faces polished to a flat surface while holding the optical fiber 16 therein.
A light attenuation plate 21 is provided in front of one end face, and the other end face is inserted halfway into the split sleeve 16 as shown in the figure.

As shown in the external view of FIG. 2, the split sleeve 16 is a pipe made of an elastic metal or the like and has an axial notch 23 and an inner diameter slightly smaller than the outer diameter of the ferrule 14. The split sleeve 16 is surrounded and held with a small gap by the housing 6 bases 17 and 18 so that it does not fall out from the ferrule 14.

The light attenuation plate 21 is, as shown in the main part explanatory diagram of FIG.
Attenuation unit 2 that attenuates incident light by an arbitrary amount of light and passes it through.
5 is held in a holder 24, and is detachably held in a groove 22 of the casing 17 so that any attenuation section can be selected and set when the light emitting element module is used. Further, the attenuation plate 21 is provided obliquely with respect to the optical axis so that the light incident on the attenuation plate 21 is reflected by both surfaces of the attenuation portion 25 and the reflected light does not return to the semiconductor light emitting chip 11 .

Hereinafter, the operation will be explained by returning to FIG. 1 again. The light emitted from the light emitting chip 11 is converged by the rod lens 13, and further adjusted to the desired amount of light by the light attenuation plate 21.

The light enters the optical fiber 16. The optical fiber 15 is
The ferrule 14 is held on the central axis of the A/14 and inserted into the split sleeve 16. Therefore, Fe) V-
/l/14 Optical connector 77, -7 connector fue /' -) V 19 divided into 16 sleeves 16
By inserting the optical fiber 2od and the optical fiber 16 fixed on the central axis thereof, the optical fiber 2od and the optical fiber 16 are arranged coaxially with good reproducibility, and the light is efficiently coupled between the optical fiber 16 and the optical fiber 2o.

The light emitting element module shown in Fig. 1 can be coupled with, for example, a single mode optical fiber with a small core diameter, with good reproducibility.
By using this light-emitting element module as a light source for an optical signal of an optical transmitter in a communication system using an optical fiber as a signal transmission path, the optical signal level can be stabilized.
The effect of constructing a highly reliable communication system can be obtained.

Note that in this embodiment, a rod lens was used to make the light from the light emitting chip enter the optical fiber.
Any lens having a light condensing effect, such as a spherical lens or an aspherical lens, may be used.

Furthermore, to avoid the reflected light on the light attenuation plate.

In this embodiment, the light attenuation plate is provided obliquely to the optical axis, but it may also be provided perpendicularly to the optical axis by applying a light antireflection film to both surfaces of the light attenuation plate.

Further, in this embodiment, both end faces of the ferrule were plane polished, but any concave ferrule polishing or oblique polishing that has the effect of preventing light reflection may be employed.

According to the present invention, light emitted from a light emitting chip is made incident on a short optical fiber held in a ferrule via a condensing lens and a light attenuating plate, and a split sleeve is used. Since this 7 ferrule and the ferrule of the optical connector connected from the outside are coaxially connected, 2
The optical axis shift due to the two errules is less likely to occur, and the effect of stabilizing the coupling efficiency of light to a single mode optical fiber with a small core diameter can be obtained.

In addition, the light attenuation plate with any amount of attenuation can be attached and removed without affecting the light emitting chip, making it easy to adjust the amount of light required, resulting in superior light emission compared to conventional methods. We can provide element modules.

9 be.

Further, if the light emitting element module of the present invention is used as an optical signal source of an optical transmitter in an optical fiber communication system, it is possible to construct a highly reliable communication system with a stable optical signal level.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the configuration of a light emitting element module according to an embodiment of the present invention, Fig. 2 is an external view of a split sleeve, Fig. 3 is an explanatory diagram of the main parts of a light attenuation plate, and Fig. 4 is a conventional one. FIG. 2 is an explanatory diagram of the configuration of a light emitting element module of FIG. 11... Semiconductor light emitting chip, 12...
stem. 13... Rod lens, 14... Ferrule 16... Optical fiber, 16...
Split sleeve. 17 and 18... Housing, 19... Phenolail, 20... Optical fiber, 21...
...Light attenuation plate. 22...Groove, 23...Notch, 24
...Holder, 26...Dampening section. Name of agent: Patent attorney Shigetaka Awano and one other person) −′ こζ= く＼t ″） ′ く'r't ~ =T=]

Claims (4)

[Claims] (1) A ferrule that has a constant outer diameter, holds an optical fiber approximately on its central axis, and has both end faces polished together with the end face of the optical fiber, and a light ferrule provided in front of one end face of the ferrule. an attenuating plate and a condensing lens; a cylindrical split sleeve made of an elastic material having a notch in the axial direction, an inner diameter slightly smaller than the outer diameter of the ferrule, and inserted halfway into the vicinity of the other end surface of the ferrule; A light emitting element module comprising: a semiconductor light emitting element arranged such that emitted light enters the optical fiber via the lens and the light attenuation plate. (2) The light emitting element module according to claim 1, wherein the light attenuation plate is detachable. (3) The light-emitting element module according to claim 1, wherein the light attenuation plate is provided obliquely with respect to the optical axis, or an antireflection film is applied to both surfaces of the light attenuation plate. . (4) An optical transmitter characterized in that the light emitting element module according to claim 1 is used as an oscillation source of an optical signal.