JP2004251919A - Module for transmitting optical signal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a module for transmitting an optical signal. <P>SOLUTION: The module for transmitting the optical signal is provided with a carrier, at least one transmitting or receiving element attached on this carrier, an optical axis, at least one optical waveguide having a 1st end part representing an optical input part of the module and a 2nd end part representing an optical output part of the module, and a wavelength selecting element which is arranged in the optical waveguide and is configured so as to connect the light of a specific data channel from the optical waveguide to the transmitting or receiving element, or so as to make the light radiated from this transmitting or receiving element incident to the optical waveguide, and thereby the light is made incident to the optical waveguide substantially perpendicularly to the optical axis of the optical waveguide or coupled outward from the optical waveguide. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
(Background of the Invention)
(Field of the Invention)
The invention relates to a module for transmitting optical signals and to a transmitting and / or receiving device having such a module.
[0002]
The module for bi-directional optical data traffic uses, for example, a star-shaped structure, in which the data stream is directed in both directions (towards a central feed point in the optical fiber (upstream) and further receivers (downstream)). Operate to be sent. Thus, the same or different wavelengths can be used for individual data channels. There is a need to reduce costs while achieving increasingly higher data rates. Wavelength division multiplexing, in particular, is used for this purpose, in which optical signals of several wavelengths are transmitted simultaneously on one optical fiber.
[0003]
In this case, it is necessary to divide again into optical signals of a plurality of wavelengths in the receiver. Furthermore, it is possible to transmit an optical signal from the receiver in the direction of the point of supply.
[0004]
Therefore, there is a need for an electro-optic module having a plurality of optical ports.
[0005]
U.S. Pat. No. 4,767,171 (see European Patent Application EP 238,977) discloses a transmitting and receiving module for a bidirectional communication network having free-beam optics. Here, the spherical lens is arranged at a fixed distance from the laser diode and the end of the optical fiber, and focuses the laser light on the end of the fiber. The wavelength selection beam splitter is disposed between the spherical lenses for wavelength separation, is transmitted from the end of the optical fiber, and separates a beam path light having a wavelength different from the wavelength of the laser light (beam path light), and separates this light. Supply the detector or receiving element.
[0006]
A disadvantage of the prior art modules is that a number of sophisticated and complex assembly steps are required sequentially, each of which requires the use of considerable resources. If an assembly step in the process fails, the previous assembly step must also be rejected.
[0007]
(Summary of the Invention)
The present invention provides the following:
1. A module for transmitting optical signals,
Career and
At least one transmitting or receiving element mounted on the carrier;
At least one optical waveguide having an optical axis, a first end representing an optical input of the module, and a second end representing an optical output of the module;
The optical waveguide is disposed within the optical waveguide and couples light of a specific optical data channel from the optical waveguide to a transmitting or receiving element, or causes light emitted from the transmitting or receiving element to enter the optical waveguide. And a wavelength selection element configured as
The module whereby the light is incident into or coupled out of the optical waveguide substantially perpendicular to the optical axis of the optical waveguide.
[0008]
2. Item 2. The module according to item 1, wherein the optical waveguide is disposed in the optical waveguide section.
[0009]
3. Item 2. The module according to item 1, wherein the optical waveguide is disposed on the optical waveguide portion.
[0010]
4. Item 2. The module according to item 1, further comprising an optical waveguide portion mounted on the carrier.
[0011]
5. The module of claim 1, wherein the module is configured to be plugged into a further module.
[0012]
6. The module of claim 1, wherein an opening is formed in the light guide portion, the light guide portion being cooperable with the center pin and being connectable to further light guide portions of the further module through these openings. .
[0013]
7. Item 2. The module according to item 1, wherein the wavelength selection element is a wavelength selection mirror mounted in the optical waveguide.
[0014]
8. Item 2. The module according to item 1, wherein the wavelength selection element is a wavelength selection mirror formed integrally with the optical waveguide.
[0015]
9. Item 2. The module according to item 1, wherein the wavelength selection element is a fiber Bragg grating.
[0016]
10. Item 5. The module according to Item 4, wherein the carrier is a housing, and the optical waveguide portion is mounted on the housing.
[0017]
11. The module of claim 1, wherein the carrier has connection contacts configured to establish electrical contact between a transmitting or receiving element and a printed circuit board.
[0018]
12. The module of claim 1, wherein the optical waveguide is an integrated optical conductor.
[0019]
13. Item 2. The module according to Item 1, wherein the optical waveguide is an optical fiber.
[0020]
14． Item 2. The module according to item 1, wherein the optical waveguide is a single mode fiber.
[0021]
15. A module according to claim 4, wherein a plurality of light guides are arranged parallel to each other in the light guide portion, each of the light guides having a respective associated transmitting or receiving element.
[0022]
16. A transmitting and / or receiving device for transmitting and / or receiving light for at least two data channels, comprising a plurality of modules according to item 1, arranged behind one another.
[0023]
17. 17. The transmission and transmission of item 16, wherein one of the plurality of modules includes means for connecting an optical fiber, whereby the optical fiber is coupled to at least one optical waveguide of the one module. And / or receiving device.
[0024]
It is an object of the present invention to provide a module for optical signal transmission, which overcomes the above-mentioned deficiencies and disadvantages of prior art devices and methods of this general type. This module provides at least two data channels to the receiver, has a simple, compact modular design, and can be manufactured cost-effectively.
[0025]
In view of the above and other objects, the present invention provides a module for transmitting an optical signal. This module is
Career and
At least one transmitting or receiving element mounted on the carrier;
At least one optical waveguide having an optical axis, a first end representing an optical input of the module, and a second end representing an optical output of the module;
The optical waveguide is disposed within the optical waveguide and couples light of a particular optical data channel from the optical waveguide to a transmitting or receiving element, or causes light emitted from the transmitting or receiving element to enter the waveguide. And a wavelength selection element configured as
Thereby, the light is incident into or coupled out of the optical waveguide substantially perpendicular to the optical axis of the optical waveguide.
[0026]
In other words, it is an object of the present invention to provide at least one optical waveguide in a module, the two ends of which represent the optical input and the optical output of the module, Each has an associated transmitting or receiving element. The wavelength selection element is arranged or formed in the optical waveguide, and enters light into the optical waveguide or outputs light from the optical waveguide. The light does not affect other data channels and is emitted from or received by the transmitting or receiving element for a particular optical data channel. The light is then incident on the optical waveguide substantially at right angles to the optical axis of the optical waveguide or exits the optical waveguide.
[0027]
The expression "substantially vertical" in this case means that the light impinging on the wavelength-selective element is at such an angle that it can be deflected into the optical waveguide or vice versa.
[0028]
The solution according to the invention provides a design concept based on the use of an optical "T-element" type, wherein a horizontal "T-shaped" is provided by a continuous optical waveguide. Light is output from the optical waveguide between the optical input and the optical output substantially at right angles to the optical axis of the optical waveguide, and is incident on the optical waveguide. The interfaces of this module are the two optical interfaces at the two ends of the optical waveguide, the electrical interfaces that create the electrical contacts between the transmitting or receiving element and, in particular, the printed circuit board.
[0029]
Since the optical modules can be cascaded, the transmitting and / or receiving device according to the invention has a plurality of modules arranged one behind the other. The fact that the individual modules can be combined as required means that, depending on the application, in principle, for any desired number of data channels, multiplexers and / or demultiplexers can be provided, and one wavelength of light can be provided. Can be incident on or output from each module. The individual module or "T-element" combination option further allows the data rate to be upgraded or retrospectively provided on a customer-specific basis.
[0030]
A further advantage of the invention is that individual modules can require very little resource usage and can be manufactured cost-effectively. A bad module can itself be replaced and does not affect the functioning of the transmitting and / or receiving device.
[0031]
According to a further feature of the invention, at least one optical waveguide is arranged in or on the optical waveguide part mounted on the carrier of the transmitting or receiving element. As a result, the module has a compact configuration. Encapsulation for external influences is also provided.
[0032]
The module according to the invention can advantageously be connected by being plugged into a further module. In this regard, the light guide section preferably has a hole through which the light guide section can be connected by a center pin to a further light guide section of a further module. In this way, a plurality of modules according to the invention can easily be plugged into one another, forming the desired transmitting and / or receiving device.
[0033]
According to a further feature of the invention, the wavelength-selective element is a wavelength-selective mirror located in or formed by the optical waveguide. For example, the wavelength selection mirror is formed on a push-in element. The indentation element is preferably pushed into the optical waveguide section at an angle of about 45 ° in the process of blocking the optical waveguide.
[0034]
The optical waveguide section forming two optical waveguide sections each having at least one inclined end face, with the optical waveguide sections being coupled to each other at the inclined end faces in the axial direction, is also provided by a wavelength selecting element, It is within the scope of the present invention. One of the adjacent end faces of the optical waveguide section is in this case coated with a wavelength-selective filter, and thus passes through or emerges from the inclined end face at an angle to the optical axis of the optical waveguide. Depending on the light for the optical data channel, the light is incident on or out of the waveguide for the particular optical data channel.
[0035]
In a further embodiment of the wavelength selection element, the wavelength selection element is formed by a fiber Bragg grating. This fiber Bragg grating is obliquely in the optical waveguide. In this case, a further laser beam, in particular two crossed lasers, creates a periodic refractive index change in the optical waveguide. The result is a grating structure in which light is output or incident on a wavelength selective basis.
[0036]
A further possibility to provide a wavelength selective element is to fit a notch in the optical waveguide. The notch is provided with a wavelength selective coating.
[0037]
In one preferred refinement of the module, the carrier for the transmitting or receiving element has a housing in which the light guide section is mounted. This provides reliable protection against external influences. The carrier preferably and furthermore has connecting contacts for creating electrical contact between the transmitting or receiving element and a printed circuit board formed, for example, by a lead frame.
[0038]
The optical waveguide disposed in the optical waveguide unit is, in one embodiment, an integrated optical conductor using, for example, glass-on-silicon technology. However, it is also possible for the optical waveguide to be an optical fiber, for example a single-mode fiber, for example, having a waveguide section containing a plastic.
[0039]
It is important to note that a plurality of optical waveguides are arranged parallel to each other in the optical waveguide section, each optical waveguide having an associated transmitting or receiving element, so that the module can also be connected to an optical waveguide array. Included in the scope of the invention.
[0040]
Other features that are considered as characteristic for the invention are set forth in the appended claims.
[0041]
The present invention is illustrated and described herein as embodied in a module for optical signal transmission, but is not intended to be limited to the details shown. This is because various modifications and structural changes can be made without departing from the spirit of the present invention and within the scope and range of equivalents of the claims.
[0042]
However, the structure and method of operation of the present invention, together with further objects and advantages thereof, will be best understood from the following description of certain embodiments when read in connection with the accompanying drawings.
[0043]
(Description of a preferred embodiment)
Referring now in detail to the figures of the drawings, and firstly with particular reference to FIGS. 1a and 1b, a module according to the invention is found in which the waveguide 2 has an optical waveguide section 1 running horizontally. At one of its ends, the waveguide 2 has a first optical input or output 21 and at its second end the waveguide 2 has a second optical input or output. It has a part 22. In this case, the waveguide 2 terminates planarly with the waveguide body 1 at both ends.
[0044]
Furthermore, the wavelength selection element shown in FIG. 2 and described in more detail in the text below with reference to FIG. 2 is arranged or formed in the waveguide 2. The wavelength selection element outputs light of a specific wavelength from the optical waveguide 2 and passes this light in the direction of the transmitting or receiving element (or vice versa) and is transparent to light of other wavelengths, Does not affect the light.
[0045]
In the exemplary embodiment shown, the waveguide body 1 has a cubic shape and is mounted on the upper surface 31 of the carrier 3 by the planar lower surface 11. In addition to providing attachment to the waveguide body, a carrier 3 is used to house the transmitting or receiving element. The carrier 3 is optically coupled to the waveguide 2, as described in more detail with reference to FIG. The carrier 3 has the form of a lead frame 4 and has electrical connection contacts. The lead frame 4 is used to connect a transmitting or receiving element to a printed circuit board (not shown) and to make electrical contact between the transmitting or receiving element and the printed circuit board.
[0046]
The holding opening 12 into which the center pin 5 is inserted is provided on the end face of the waveguide main body 1. The center pin 5 allows a plurality of modules to be plugged together, with each of the optical waveguides 2 being centered.
[0047]
Of course, it is also understood that the waveguide body may further have a particular shape different from the cubic shape. The only essential feature is that the waveguide body fixes the optical waveguide and in the process allows optical coupling between the optical waveguide and the transmitting or receiving element.
[0048]
The illustrated module represents an optical subassembly. This forms a compact unit that can be individually checked beforehand and includes a transmitting or receiving element, a carrier and an optical waveguide.
[0049]
The optical coupling between the transmitting or receiving element in the module according to the invention and the optical waveguide 2 is explained in the following text with reference to FIG. Illustrated therein is a transmission element, in particular a laser diode 8, which can be arranged on the carrier 3 and connected to the printed circuit board via connection contacts 4.
[0050]
The schematically illustrated wavelength selection element 9 is incorporated in the beam path in the optical waveguide 2 at an angle of 45 °. Element 9 has the property of injecting or outputting light at a specific wavelength λ3 at right angles into the optical waveguide, while being very transparent to light of other wavelengths λ1, λ2, In other words, it is "looped through". Thus, the wavelength selective element provides one and only one wavelength band. It is associated with one data channel and in each case enters or exits the optical waveguide 2.
[0051]
The optical axis A of the laser diode 8 runs orthogonally (perpendicularly) to the optical axis B of the optical waveguide 2. Small tolerances (up to 15 °) from a right angle arrangement are possible and acceptable. What is important is that the light is efficiently incident on the optical waveguide 2 or is efficiently output from the optical waveguide.
[0052]
The wavelength selection element 9 can have a wide range of configurations. For example, the wavelength selection element 9 can be a specific fiber Bragg grating, allowing for lateral output. In such a grating, two crossed lasers cause a change in the refractive index in the optical waveguide, which leads to wavelength selective refraction of the light. Further, the wavelength selection element may be a wavelength selection mirror that is incorporated in the waveguide section 1 and blocks the optical waveguide 2. The waveguide selection element may further be a notch in the optical waveguide, having a wavelength selective coating, or a wavelength section with a beveled end face coated to be wavelength selective.
[0053]
In order to avoid any interference in the beam path between the optical waveguide 2 and the laser diode 8, the optical waveguide section 1 and / or the carrier 3 are in each case transparent for the respective wavelength in the region of the beam path. Or designed to provide an appropriate cutout in this area. In this case, the latter can be filled with an optically transparent filling compound. The exemplary embodiment in FIG. 2 only shows a schematic diagram.
[0054]
Referring now to FIG. 3, a transmitting and / or receiving device according to the invention is shown, in which three individual modules 2a, 2b, 2c (see FIGS. 1a, 1b) are plugged together. In this case, the individual modules are connected via a center pin 5. The modules 2a, 2b, 2c are connected to each other and to the optical fiber 7 via an optical connector 6, which may have a center pin 61. Optical signals can be transmitted in both directions in the optical fiber 7.
[0055]
The light guides, including the light guides 2 of the individual modules (see FIG. 1a), pass through the modules 2a, 2b, 2c which are connected to one another. Thus, the optical signals of the plurality of data channels may be received by the modules 2a, 2b, 2c via the optical fiber 7 and / or the optical signals may be transferred from the module to the optical fiber 7. Thus, any desired multiplexer / demultiplexer configuration can be manufactured from the module.
[0056]
In the exemplary embodiment in FIG. 3, the right module 2c has a transmitting element. The light of the transmitting element is incident on the optical fiber 7 at the first wavelength λ3 by the wavelength selection filter in the module 2c. Each of the other modules 2a, 2b has a receiving element. In this case, the light of the second wavelength λ2 is output to the receiving element of the module 2b by the respective wavelength selection filters in the modules 2a and 2b, and the light of the third wavelength λ1 is output on a wavelength selection basis to the module 2a. To the receiving element.
[0057]
Therefore, in this case, the optical signal of the wavelength λ3 enters the optical fiber 7, and the optical signals of the two wavelengths λ1 and λ2 are output from the optical fiber 7 and separated by these wavelengths. However, if a suitable filter is available, the arrangement of the modules can be changed.
[0058]
FIG. 4 shows a cross section passing through the optical waveguide section 1 of the module of the present invention. The optical waveguide unit 1 contains, for example, plastic or silicon. The optical waveguide 2 is, for example, a glass fiber, which is inserted into the optical waveguide unit 1. However, these glass fibers can also be optically integrated (eg, glass-on-silicon).
[0059]
FIG. 4 shows firstly a holding opening 12 for the center pin 5. Further, a waveguide region 13 is schematically illustrated, wherein one waveguide or a plurality of waveguides parallel to each other are present or arranged. If multiple waveguides are present, a corresponding number of transmitting or receiving elements 9 are provided on the carrier 3 or arranged in an array.
[0060]
In conclusion, the present invention provides the following.
[0061]
A module for transmitting an optical signal has a transmitting or receiving element mounted on a carrier. The two ends of the at least one optical waveguide represent an optical input and an optical output of the module, the optical waveguide being associated with a transmitting or receiving element. The wavelength selection element is disposed or formed in the optical waveguide, and enters light into the optical waveguide or outputs light from the optical waveguide. This light is emitted from or transmitted by the transmitting or receiving element for a particular optical data channel. The light enters or exits the optical waveguide substantially perpendicular to the optical axis of the optical waveguide.
[Brief description of the drawings]
FIG. 1a is a schematic side view of an optical module according to the present invention.
FIG. 1b is a plan view of the module shown in FIG. 1a.
FIG. 2 is a schematic diagram of the coupling of a transmitting or receiving element in a module with an optical waveguide according to the invention.
FIG. 3 is a schematic view of an assembly of a plurality of modules according to the present invention in a transmitting and / or receiving device.
FIG. 4 is a cross-sectional view through the optical waveguide section of the module according to the present invention.

Claims (17)

A module for transmitting an optical signal,
Career and
At least one transmitting or receiving element mounted on the carrier;
At least one optical waveguide having an optical axis, a first end representing an optical input of the module, and a second end representing an optical output of the module;
The light of a specific optical data channel from the optical waveguide is coupled to the transmitting or receiving element, or the light emitted from the transmitting or receiving element is incident on the optical waveguide. And a wavelength selection element configured as
A module whereby the light is incident into or coupled out of the light guide substantially perpendicular to the optical axis of the light guide. The module according to claim 1, wherein the optical waveguide is disposed in an optical waveguide unit. The module according to claim 1, wherein the optical waveguide is disposed on an optical waveguide unit. The module according to claim 1, further comprising an optical waveguide section mounted on the carrier. The module of claim 1, wherein the module is configured to be plugged into a further module. 5. The module according to claim 4, wherein the light guide is formed with an opening, the light guide being connectable to a further light guide of a further module via the opening cooperating with a center pin. . The module according to claim 1, wherein the wavelength selection element is a wavelength selection mirror mounted in the optical waveguide. The module according to claim 1, wherein the wavelength selection element is a wavelength selection mirror integrally formed with the optical waveguide. The module according to claim 1, wherein the wavelength selection element is a fiber Bragg grating. The module according to claim 4, wherein the carrier has a housing, and the optical waveguide section is mounted on the housing. The module according to claim 1, wherein the carrier has connection contacts configured to establish electrical contact between the transmitting or receiving element and a printed circuit board. The module according to claim 1, wherein the optical waveguide is an integrated optical conductor. The module according to claim 1, wherein the optical waveguide is an optical fiber. The module according to claim 1, wherein the optical waveguide is a single mode fiber. 5. The module according to claim 4, wherein the plurality of light guides are arranged parallel to each other in the light guide portion, each of the light guides having a respective associated transmitting or receiving element. A transmitting and / or receiving device for transmitting and / or receiving light for at least two data channels, comprising a plurality of modules according to claim 1 arranged one behind the other. 17. The transmission and transmission of claim 16, wherein one of the plurality of modules comprises means for connecting an optical fiber, whereby the optical fiber is coupled to at least one optical waveguide of the one module. And / or receiving device.

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