JP2001066468A - Optical receptacle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost and to improve noise characteristics in an optical receptacle used in an optical receiver and transmitter. SOLUTION: This optical receptacle is provided with a sleeve 31 which is fitted into the ferrule of a mating optical connector and holds it and a metal made holder 24 which holds the sleeve 31, and the holder 24 and an optical element unit 12 are assembled by welding directly or via other metal parts. In this case, the holder 24 is constituted so that it covers and holds the part ranging from the optical element unit 12 side to the middle of the sleeve 31 when viewed from the axial direction, a sleeve cover 40 consisting of a resin formed part is provided so as to cover the part of the sleeve 31 which is not covered by the holder 24, and the fitting pawl 41 formed in the sleeve cover 40 is engaged with the fitting pawl 25 formed in the holder 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receptacle having a light emitting element or a light receiving element.

[0002]

2. Description of the Related Art In recent years, it has become very common to use optical transmission in data communication, and an optical transceiver, which is a key device thereof, has been used in an extremely large amount. Also, with the spread of the Internet, the speed of transmission signals to be handled has been remarkably increased. For this reason, there is a demand for an optical transceiver to simultaneously realize low cost, high speed operation, and small size.

In communication using an optical fiber, an optical connector is provided on an optical fiber cable side on both sides of an optical transceiver and an optical receiver, and a receptacle fitted to the optical connector is provided on the optical transceiver or the optical receiver. It is common to provide.

In an optical transceiver, an optical receptacle portion, that is, a portion fitted to an optical connector and optically coupling an optical element (light emitting element, light receiving element) with an optical fiber is a very important part that determines the performance and cost. It is.
It is necessary to realize high efficiency and high reliability optical coupling, as well as low cost and small size. Recently, with the increase in the speed of transmission signals to be handled, characteristics that do not generate interference noise and characteristics that are not affected by interference noise have also become important.

FIG. 5 shows an example of the prior art, which is fitted with an optical connector (SC connector) on the optical fiber side and optically couples the output light of a laser diode (LD) 9 to the mating SC connector. 1 shows a structure of an optical receptacle to be used.

A split sleeve 31 that fits and holds a ferrule (not shown) of a mating optical connector, a metal holder 21 that holds the split sleeve 31, and a sleeve that covers the sleeve 31 and the stub ferrule holder 21 A stub ferrule 30 is fixed in the holder 24 with the cover 20. Reference numeral 12 denotes an optical element unit, which includes an LD 9 serving as an optical element that emits light to the other ferrule or receives light from the other ferrule.
Package 10, LD color 23, and condenser lens 11
And is configured. The sleeve cover 20, the stub ferrule holder 21, the LD adapter 22, and the LD collar 23 are assembled by welding.

[0007] In terms of material, the sleeve cover 20, the stub ferrule holder 21, the LD adapter 22, the LD collar 23 and parts made by cutting out a stainless steel material, and a stub ferrule 30 made of zirconia ceramics.
And a split sleeve 31 also made of zirconia ceramic, which realizes low-loss, low-reflection and stable coupling with a mating SC connector to which a single-mode optical fiber is connected. Since the tip of the ferrule of the mating SC connector is connected to the stub ferrule 30 by a PC (Physical Contact), and the optical input portion of the stub ferrule 30 is polished obliquely, the optical output of the LD 9 does not return to the LD 9 itself.

Therefore, it is possible to prevent a phenomenon such as an increase in noise of the output light of the LD 9. Constituent members 20, 21, 2
Reference numerals 2 and 23 are high-precision and hard stainless steel materials. Since welding (such as YAG welding) is used for fixing, there is little problem of optical axis shift due to temperature and the like, and a highly reliable LD receptacle with high mechanical strength is provided. realizable. The structure as described above has the greatest merit especially when the light source serving as the optical element in the receptacle for a single mode optical fiber is a laser light source, but is also effective when other optical fibers and light sources are used.

[0009]

However, the conventional technique has a disadvantage that the optical receptacle becomes expensive. That is, the conventional sleeve cover 20 is formed by cutting a stainless steel material. The sleeve cover 20 also functions as a main body of the entire LD receptacle, and it is necessary to form a shape for fixing the inside of the optical transceiver in the outer shape. For this reason, the shape tends to be complicated, and the processing by cutting out the stainless steel material is troublesome and the component cost is relatively high. Further, in order to fix the stub ferrule 30 to the sleeve cover 20, two press-fitting operations are required structurally, and the assembly cost is increased.

[0010] Further, in the conventional technique, a problem of noise is likely to occur. That is, although the LD package 10 is conductive and is generally connected to the ground or power supply of the circuit, the LD collar 23 is welded to the LD package 10 and the connection between other metal parts is also performed by welding. The entire LD receptacle has the same potential as the circuit ground or power supply. Therefore, if there is noise on the ground or power supply,
The receptacle itself behaves like an antenna and generates noise radio waves. Since the LD is driven by a relatively large current,
The noise around the LD is large, and the above becomes a serious problem as the transmission speed increases, and a shield cover or the like may be required. In the case of a light receiving element, on the contrary, the metal cover portion acts as an antenna and picks up external noise, which leads to deterioration of reception sensitivity and the like. In recent years, the size of the housing of the optical transceiver has become extremely small, and the receptacles for transmission and reception have been placed close to each other. Therefore, the influence of noise directly applied from the transmission side to the reception side is likely to occur.
For this reason, it is required to form an optical receptacle by using no metal or by minimizing the metal part.

As described above, the optical loopback connector according to the prior art is required to be improved in both cost and noise characteristics.

An object of the present invention is to solve the above problems and to provide an optical receptacle used in an optical transceiver, which is low in cost and has excellent noise characteristics.

[0013]

Means for Solving the Problems In order to achieve the above object, the present invention is configured as follows.

(1) According to the first aspect of the present invention, there is provided a sleeve which fits and holds a ferrule of a mating optical connector;
An optical element unit having an optical element that emits light to the ferrule or receives light from the ferrule, and a metal holder that holds the sleeve, wherein the optical element unit and the holder are directly or other metal In an optical receptacle assembled by welding via parts, the holder is configured to cover and hold at least a part of the sleeve from the optical element unit side as viewed in the axial direction, and is covered by the holder of the sleeve. A sleeve cover of a resin molded article is provided so as to cover an untouched portion and the sleeve, a fitting claw is formed on the sleeve cover, and a fitting claw fitted with the fitting claw is formed on the holder. It is characterized by.

This includes the following two forms.
First, the holder is configured to cover and hold a part of the sleeve from the optical element unit side when viewed in the axial direction, so as to cover a portion of the sleeve that is not covered by the holder and the sleeve. A sleeve cover of a resin molded product is provided on the sleeve cover, a fitting claw is formed on the sleeve cover, and a fitting claw to be fitted with the fitting claw is formed on the holder. Second, the holder is configured to cover and hold at least the entire area of the sleeve from the optical element unit side as viewed in the axial direction, and a sleeve cover of a resin molded product is provided so as to cover the holder. A fitting claw is formed on the sleeve cover, and a fitting claw fitted to the fitting claw is formed on the holder. The former means a form in which the sleeve protrudes from the holder, and the latter means a form in which the holder covers at least the entire area of the sleeve.

In both of the optical receptacles, since the sleeve cover for covering the sleeve and the holder is made of a resin molded product, it can be manufactured at an extremely low cost as compared with the case where it is made of metal. is there. Also, since the stub ferrule holder can be easily fitted simply by pushing it into this sleeve cover,
Assembly of this part is also very easy.

Furthermore, since the sleeve cover is molded of resin, the ratio occupied by the metal portion can be greatly reduced. For this reason, since a portion that can be a noise antenna becomes small, the amount of electromagnetic waves radiated or received from the surroundings is reduced. In particular, when high-speed optical transmission is performed by a small optical transceiver in which a light-emitting element and a light-receiving element are placed close to each other, it is effective to reduce interference noise between transmission and reception, and to reduce deterioration of reception sensitivity when the transmission circuit operates. It can be suppressed.

(2) The invention described in claim 2 is the invention according to claim 1.
In the optical receptacle described above, the sleeve is a split sleeve, and a stub ferrule is fixed to the holder, and the split sleeve is held by the holder by being fitted into the stub ferrule.

This is a form in which a stub ferrule and a split sleeve are used at a portion of the mating optical connector where a ferrule is inserted, so that stable optical coupling with low loss can be obtained.

(3) The invention described in claim 3 is the invention according to claim 1.
3. The optical receptacle according to claim 2, wherein the fitting claws of the sleeve cover are formed of a pair of arcuate female claws, and the fitting claws of the holder are formed of male claws which are fitted with the female claws. It is characterized by the following.

According to this feature, since the fitting claws of the sleeve cover are formed in an arc shape, they match with metal parts having a cylindrical shape, hold securely, and have an outer shape around the fitting claws. It is also possible to keep the dimensions small. Further, the structure of a molding die for realizing such a shape is also simple.

(4) According to a fourth aspect of the present invention, in the optical receptacle according to the first, second or third aspect, a hook for fitting with a mating optical connector is integrally formed on the sleeve cover. It is characterized by the following.

According to this feature, since the hook, for example, the hook for the SC connector is integrally formed of the same resin as the sleeve cover, a hook having flexibility can be easily obtained at low cost. No hassle is required when installing in a transceiver.

The gist of the present invention is that the sleeve cover has a fitting claw integrally formed of resin, and this fitting claw is fitted with the fitting claw of the holder holding the stub ferrule. By using such a structure, it is possible to realize an optical receptacle with low cost and good noise characteristics.

[0025]

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

FIG. 1 is a sectional view of an optical receptacle according to one embodiment of the present invention, FIG. 2 is a detailed view of a sleeve cover shape according to one embodiment of the present invention, and FIG. 3 is a stub ferrule according to one embodiment of the present invention. It is a detailed view of a holder shape.

A condensing lens 11 is attached to an LD package 10 including an LD 9 as an optical element that emits light to a ferrule (not shown) of the other party.
D package 10, LD color 23, and condenser lens 1
1 constitutes an optical element unit 12.
Although the optical element can be applied to either a light emitting element or a light receiving element, the present embodiment is directed to an LD (laser diode).

As in the conventional case, a split sleeve 31 that fits and holds a ferrule of a mating optical connector, a metal stub ferrule holder 24 that holds the split sleeve 31, and a stub ferrule holder 24 Fixed stub ferrule 30 and split sleeve 31
And a sleeve cover 20 that covers the stub ferrule holder 24.

In terms of material, it is made by cutting out stainless steel materials such as the sleeve cover 20, the stub ferrule holder 24, the LD adapter 22, and the LD collar 23.
These are fixed by welding. Further, a stub ferrule 30 made of zirconia ceramic and a split sleeve 31 also made of zirconia ceramic are provided so that low-loss, low-reflection, and stable coupling with the mating SC connector to which the single-mode optical fiber is connected can be realized. It has become. The tip of the ferrule of the mating SC connector is PC-connected to the stub ferrule 30 and the optical input of the stub ferrule 30 is polished obliquely, so that the optical output of the LD 9 does not return to the LD 9 itself.

However, unlike the related art, the stub ferrule holder 24 is configured to cover and hold a part of the split sleeve 31 from the optical element unit 12 side when viewed in the axial direction. Further, a sleeve cover 40 of a resin molded product is provided so as to cover a portion of the split sleeve 31 which is not covered with the stub ferrule holder 24. The fitting claws 41 are formed on the sleeve cover 40, and the fitting claws 25 to be fitted on the fitting claws 41 are formed on the stub ferrule holder 24.

The LD package 10 and the LD collar 23 are joined by resistance welding, and they are aligned and welded to the stub ferrule holder 24 via the LD adapter 22. The stub ferrule 30 is press-fitted and fixed to the stub ferrule holder 24.

The sleeve cover 40 is made of resin and has two arcuate fitting claws 41. That is,
As shown in FIG. 2, a skirt portion 50 is formed below the sleeve cover 40 so as to be attached to the outer periphery of the stub ferrule holder 24. It is divided into a pair of arc-shaped portions 52 divided into two. A fitting hole 42 is formed in each of the two arc-shaped portions 52 in the form of a slit extending in the circumferential direction. It functions as a claw 41.

On the other hand, as shown in FIG. 3, a fitting claw 25 to be fitted with the fitting claw 41 is formed on a corresponding portion of the stub ferrule block made of metal, that is, on the outer periphery of the stub ferrule holder 24. I have. This fitting claw 25 is provided on the outer periphery of the stub ferrule holder 24.
It is provided in the form of a flange that extends partially along the circumferential direction. The cross-sectional shape of the fitting claw 25 itself is shown in FIG.
As can be seen from the figure, the upper surface, that is, the surface close to the optical connector on the other side is formed as a tapered surface 53, and the opposite side is a substantially triangular shape formed as a right-angled surface 54. It is designed to be prevented from falling off.

As described above, the fitting claw 41 of the sleeve cover 40 is a female claw having a fitting hole 42, and is fitted to the male fitting claw 25 of the other stub ferrule block. The holder 24 is fixed to the sleeve cover 40.

As in the prior art, since the stub ferrule 30 and the split sleeve 31 made of zirconia are used in the part where the ferrule of the mating optical connector is inserted, stable optical coupling with low loss can be obtained. LD package 10 and stub ferrule 30 requiring optical coupling accuracy
The parts that determine the positional relationship with the metal parts (24,
22, 23), which are joined with high precision by YAG welding, so that highly reliable optical coupling characteristics can be obtained.

On the other hand, the sleeve cover 40 serving as the LD receptacle main body case has a relatively complicated shape, but can be manufactured at extremely low cost because it is molded with resin. The stub ferrule holder 24 can be easily fitted simply by pushing the stub ferrule holder 24 into the sleeve cover 40, so that the assembly of this portion is extremely easy.

Further, the fitting pawl 41 of the sleeve cover 40
Since the is formed in an arc shape, it matches with metal parts having a cylindrical shape, it is possible to securely hold, and it is also possible to reduce the outer dimensions of the periphery of the fitting claw.
Further, the structure of a molding die for realizing such a shape is also simple. Depending on the application, the claws may be flat instead of arcuate.

Further, according to the present technology, since the sleeve cover 40 is molded of resin, the corresponding portion is made of metal compared with the conventional LD receptacle (FIG. 5) in which the corresponding portion is also made of metal. Greatly reduces the number of parts constituted by For this reason, since a portion that can be a noise antenna becomes small, the amount of electromagnetic waves radiated or received from the surroundings is reduced. In particular, when high-speed optical transmission is performed by a small optical transceiver in which a light-emitting element and a light-receiving element are placed close to each other, it is effective to reduce interference noise between transmission and reception, and to reduce deterioration of reception sensitivity when the transmission circuit operates. It can be suppressed.

FIG. 4 shows another embodiment of the present invention, in which only the shape of a resin sleeve cover is shown. Parts other than the resin sleeve cover 43 are exactly the same as those in FIG.

The sleeve cover 43 in this embodiment
Has a hook 4 for holding the stub ferrule block.
In addition to the above, two hooks 44 for fitting and holding the SC type optical connector are integrally formed. More specifically, the hook 44 is composed of an arm portion 44a extending from a rectangular plate-like base portion 45 and an engaging portion 44b protruding inward at a tip end thereof.

The hook 44 for the SC connector must be formed of resin in order to obtain flexibility. However, in the prior art, it is a separate part from the sleeve cover, and it takes time to incorporate the hook into the optical transceiver. Was. However, according to the present embodiment, since the hooks 44 are integrated with the sleeve cover 43, there is no need to incorporate the hooks into the optical transceiver. Therefore, it is advantageous for cost reduction.

In the embodiment shown in FIG. 1, an LD receptacle using a stub ferrule is taken as a typical example. However, the present invention can be applied to a method using no stub ferrule, or a method using a light emitting diode (LED) or a light receiving element. Is valid.

In the embodiment shown in FIG. 1, the condensing lens 11 is mounted on the cap of the LD package 10. However, the same is true even when the condensing lens 11 is fixed to another component.

Further, although FIG. 1 shows an LD receptacle fitted to an SC connector, the same structure can be applied to a receptacle for another connector if the dimensions are changed.

In FIG. 1, the holder 24 is configured to cover and hold the optical element unit 12 from the optical element unit 12 side to the middle of the sleeve 31 when viewed in the axial direction. Alternatively, it can be configured to cover and hold more than that. Even under this configuration, since the sleeve cover 40 is a resin molded product, an optical receptacle having excellent noise characteristics at low cost can be obtained. .

[0046]

As described above, according to the present invention, it is possible to realize an optical device module having excellent noise characteristics at low cost as follows.

(1) According to the optical receptacle of the first aspect, since the sleeve cover for covering the sleeve and the holder is made of a resin molded product, it can be manufactured at extremely low cost as compared with the case where it is made of metal. It is. The stub ferrule holder can be easily fitted simply by pushing it into the sleeve cover, so that the assembly of this part is extremely easy.

Further, since the sleeve cover is molded with resin, the ratio occupied by the metal portion can be greatly reduced. For this reason, since a portion that can be a noise antenna becomes small, the amount of electromagnetic waves radiated or received from the surroundings is reduced. In particular, when performing high-speed optical transmission with a small optical transceiver in which the light emitting element and the light receiving element are placed close to each other,
This is effective for reducing interference noise between transmission and reception, and can suppress deterioration of reception sensitivity when the transmission circuit operates.

(2) According to the optical receptacle of the second aspect, since the stub ferrule and the split sleeve are used at the portion where the ferrule of the mating optical connector is inserted, the optical coupling is stable with low loss. Is obtained.

(3) According to the optical receptacle of the third aspect, the fitting claws of the sleeve cover are formed of a pair of arcuate female claws, and the fitting claws of the holder are fitted with the female claws. It is composed of male claws that fit together, and the fitting claws on the sleeve cover are arc-shaped, so they match metal parts with a cylindrical shape, hold securely, and around the fitting claws. It is also possible to keep the external dimensions of the part small. Further, the structure of a molding die for realizing such a shape is also simple.

(4) According to the optical receptacle of the fourth aspect, the hook for fitting with the other optical connector is integrally formed on the sleeve cover, so that the flexible hook can be easily formed. In addition to being obtained at low cost, there is no trouble in assembling into an optical transceiver.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an optical receptacle according to an embodiment of the present invention.

FIG. 2 is a detailed view showing a shape of a resin sleeve cover according to the embodiment of the present invention, wherein (a) is a front view,
(B) is a side view, and (c) is a bottom view.

FIG. 3 is a detailed view showing a shape of a stub ferrule holder in one embodiment of the present invention, wherein (a) is a top view,
(B) is a front view, (c) is a side view, and (d) is a bottom view.

FIG. 4 is a detailed view showing a shape of a resin sleeve cover according to another embodiment of the present invention, wherein (a) is a front view,
(B) is a side view, and (c) is a bottom view.

FIG. 5 is a cross-sectional view showing a conventional optical receptacle.

[Explanation of symbols]

 9 Laser Diode (LD) 10 LD Package 11 Lens 12 Optical Element Unit 22 LD Adapter 23 LD Color 24 Stub Ferrule Holder 25 Fitting Claw 30 Stub Ferrule 31 Split Sleeve 40 Sleeve Cover 41 Fitting Claw 42 Fitting Hole 43 Sleeve Cover 44 hook

Claims (4)

[Claims] An optical element unit having an optical element that emits light to the ferrule or receives light from the ferrule; and a metal that holds the sleeve. And an optical receptacle in which the optical element unit and the holder are assembled by welding directly or through another metal part, wherein the holder is at least the sleeve from the optical element unit side when viewed in the axial direction. And a sleeve cover of a resin molded product is provided so as to cover a part of the sleeve not covered by the holder and the sleeve, and form a fitting claw on the sleeve cover. An optical receptacle, wherein the holder is provided with a fitting claw to be fitted with the fitting claw. . 2. The apparatus according to claim 1, wherein said sleeve is a split sleeve, and a stub ferrule is fixed to said holder, and said split sleeve is held by said holder by being fitted into said stub ferrule. 2. The optical receptacle according to 1. 3. A fitting claw of the sleeve cover comprises a pair of arcuate female claws, and a fitting claw of the holder comprises a male claw fitting with the female claw. The optical receptacle according to claim 1 or 2, wherein 4. An optical receptacle according to claim 1, wherein said sleeve cover is integrally formed with a hook for fitting with a mating optical connector.