KR20030032774A - Optical bi-directional transceiver module with single pigtail fiber - Google Patents

Abstract

PURPOSE: A bi-directional optical module having optical signal transmission and receiving function through a pigtail fiber is provided to reduce a cost of an optical module, to increase productivity of the module, and also to provide an appropriate performance in a high speed optical signal transmission and receiving. CONSTITUTION: The bi-directional optical module includes a light source-light filter-lens assembly structure(31), and a light source part block(21) and a light receiving part block(22) and a lens and an optical filter in a 8 pin mini-DIL(Dual In Line) package. The light source-light filter-lens assembly structure has two pillars and a lens assembly hole. The light source part block has a number of impedance-matched strip lines(23) for electrical connection between optical devices and a package pin. The light filter is a dichroic filter and is assembled in parallel with a side of the structure. The light receiving part block has a photo diode and a preamplifier on a silicon or ceramic substrate, and has a number of impedance-matched strip lines.

Description

Optical bi-directional transceiver module with single pigtail fiber

The present invention relates to the construction and fabrication of a bi-directional optical module having a function of simultaneously transmitting and receiving optical signals of different wavelengths through a single optical fiber.

An optical network that wants to exchange information at a low cost, such as an optical subscriber network or a computer network using optical fibers, is a single optical fiber that connects the central office or host with a single fiber between the central office or host and individual subscribers or terminals in order to reduce the cost of laying fiber. Have a distribution network In order to simultaneously transmit and receive information through such a single optical fiber distribution network, a wavelength division multiplexing (WDM) method that divides and uses wavelengths of signal light is used. For example, signal light transmitted to an individual subscriber / terminal uses a wavelength of 1.55 μm and signal light transmitted to a central station / host uses a wavelength of 1.3 μm. In this case, the optical module used for the terminal of each single optical fiber distribution network should have 1.3 μm optical transmission / 1.55 μm optical reception or 1.3 μm optical reception / 1.55 μm optical transmission through the attached single optical fiber.

The technical field of the present invention is an optical module for optical communication, specifically, an LD module for generating and transmitting an optical signal and a PD module for converting the received optical signal back into an electrical signal. Conventional optical modules have been manufactured separately from the above LD and PD modules, but in recent years, as optical subscriber networks and computer optical networks are characterized by low cost, optical signals are simultaneously transmitted through a single fiber (single). The demand for bi-directional optical modules that can be received is skyrocketing

1 illustrates a structure of a conventional bidirectional optical module. The conventional bidirectional optical module uses the optical filter 6 to replace the TO type LD module 11 and the TO type PD module 12 which have been commonly used. It has a mechanical combination around the center. Here, the TO-type optical module is an application of a conventional cylindrical transistor package. The LD module includes an LD (1) and an m-PD (not shown) for monitoring the optical output of the LD. The PD module is a PD (3). If necessary, a preamplifier (not shown) is added, and both are sealed by a cap to which a lens 5 or a transparent window 7 is attached. Figure 1 (a) is a bi-directional optical module manufactured by using a TO module sealed with a cap attached to the lens 5 having its own light collecting function (b) is a TO module sealed with a cap attached to a transparent window By using a lens having a condensing function is inserted between the TO module and the optical fiber ferrule (8) to produce a bidirectional optical module. Referring to the operation principle of the case of Figure 1 (a) as follows. First, the transmitted light output from the LD passes through the optical filter 6 and is focused by the lens of the cap to the ferrule 8 into which the attached optical fiber 9 is inserted, and conversely, the received light incident from the attached optical fiber to the bidirectional optical module is After reflecting off the surface of the optical filter 6, the lens of the cap is focused on the PD 3 of the TO-type PD module 12. Here, by selecting the transmission / reflection wavelengths for the incident light of 45 degrees inclination of the optical filter, simultaneous transmission and reception of optical signals for different wavelengths becomes possible. For example, when a dichroic filter having a characteristic of 1.3 μm wavelength transmission / 1.55 μm wavelength reflection is used, the LD transmits an optical signal having a wavelength of 1.3 μm, and the PD carries light having a wavelength of 1.55 μm. You will receive a signal.

Conventional bidirectional optical modules have the following disadvantages in the form of assembling individual TO-type LD and PD packages 11 and 12 around the optical filter 6. First, the use of individual TO type LD and PD packages 11 and 12 increases the volume of the module, and increases the price of the bidirectional module due to the increase in the parts and process costs required to manufacture the individual TO. It is difficult to manufacture because laser welding is required for 3 parts such as and optical ferrule. Second, since the portion joined by laser welding is not airtight, the optical filter 6, which is a key optical component of the bidirectional optical module, is mounted inside the unsealed module housing 10, and thus the reliability is low. Third, by using the TO package, which is a low-speed package of 1 Gbps or less, it is difficult to drive the LD at high speed, and it is difficult to extract the received signal of the PD at high speed.

The present invention provides a bi-directional optical module having a function of simultaneously transmitting and receiving optical signals of different wavelengths through a single attachment optical fiber required in a low cost single optical fiber distribution network such as an optical subscriber network or a computer network. In order to provide a structure and a manufacturing method of the present invention, the bidirectional optical module provides a structure using a minimum optical component and a simple manufacturing method requiring a minimum number of laser welding times, thereby lowering the price of the optical module and improving module productivity. At the same time, it aims to provide performance suitable for high speed optical signal transmission and reception.

Specifically, in the present invention, in order to solve the high price, difficulty of manufacturing, low reliability, and the limitation of the optical signal transmission and reception of Gbps or more of the conventional bidirectional optical module, first, the optical transmitter and the optical receiver of the bidirectional optical module Packaging reduces the number of parts and simplifies the assembly process, including laser welding, which requires precise light alignment, providing a method of shortening assembly time and increasing yield to improve productivity. Through this process, it becomes possible to manufacture the low cost optical module ultimately.

In addition, in the present invention, the optical filter is also mounted inside the package and sealed to prevent deterioration due to external moisture, thereby preventing reliability degradation, and to use a high-speed ceramic package by removing from a low-speed TO type package to speed up the bidirectional optical module. At the same time, the electrical connection between the package terminals and the LD and PD in the package is composed of impedance-matched strip lines considering RF characteristics to minimize parasitic elements that limit high-speed modulation.

Therefore, in the present invention, an 8-pin mini-DIL package that is small and advantageous for high-speed modulation of Gbps or more is selected as a basic package, an optical filter is mounted inside the package, and an optical system is configured with one lens, and an external circuit, LD, PD The electrical connection between them consists of strip lines, and the structure and method of fabrication of a bidirectional optical module of a new structure, in which a module is fabricated by laser welding in one area, are provided.

Other objects and advantages of the invention will be described below, and will be better understood by practice of the invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the appended claims.

1 is a conventional bidirectional optical module structure.

Fig. 2 is a layout view of a light source unit, a light receiving unit, an optical filter, a lens, a light source-optical filter-lens assembly, and an optical component of the present invention.

3 shows an 8 pin mini-DIL package.

Figure 4 is a bidirectional optical module assembly diagram (Example 1) using a light source unit, a light receiving unit, an optical filter, a lens, a light source-optical filter-lens assembly of the present invention.

Figure 5 shows the change in the shape of the optical cross-section according to the structure and optical trajectory of the elliptical light receiving element of the present invention.

Fig. 6 is a layout view of a light source unit, a light receiving unit, an optical filter, a light source-optical filter assembly, and an optical component of the present invention.

Figure 7 is a bidirectional optical module assembly (Example 2) using a light source unit, a light receiving unit, an optical filter, a lens, a light source-optical filter assembly and a lens assembly mechanism of the present invention.

8 is an arrangement of optical components of the apparatus and m-PD top assembly of the present invention (Example 3),

9 is a double-sided m-PD block structure for the top assembly,

Fig. 10 is a layout view of an optical component of an assembly in which the apparatus and m-PD of the present invention are separated (Example 4),

11 is a layout view of an optical part of the apparatus and the light receiving unit upper assembly of the present invention (Example 5),

12 is a block diagram of the double-sided light receiving unit for the upper assembly,

13 is an assembly diagram of a bidirectional plastic optical module using the receiving light upward reflection mechanism of the present invention (Example 6),

FIG. 14 shows an assembly diagram of a bidirectional optical module using the receiving light downward and upward reflection mechanism of the present invention (Example 7).

* Explanation of symbols on the main parts of the drawing

1. Laser Diode (LD) 2. Light Output Monitoring Device (m-PD)

3. Light receiving element (PD) 4. Preamplifier

5. Lens 6. Optical Filter

7. Window 8. Fiber Optic Ferrule

9. Attached fiber (figtail fiber) 10. Module housing

11.TO package for LD 12.TO package for PD

13. Ferrule Holder 14. TO Package Holder

21. Light source block 22. Light receiving block

23. Strip line 24. Auxiliary optical filter support

25.LD block 26. m-PD block for both sides

27. Via hole 28. m-PD block for section

29. Double-sided light receiving block 31. Light source-optical filter-lens assembly

32. Inclined surface for optical filter assembly 33. Lens insertion hole

34. Light source-optical filter assembly 35. m-PD block separation assembly

36. Receiving light upward reflection fixture 40. Side incident m-PD

41.Oval PD 42.Received Area

43. PD electrode 44. Wedge type optical filter

45. Auxiliary optical filter 51. mini-DIL package

52.pin 53.metal ring for laser welding

54. Through Hole 55. Plastic mini-DIL Package

56.tube for laser welding

The bidirectional optical module of the present invention is composed of an 8-pin mini-DIL (dual inline) package, which is widely used for manufacturing a miniaturized optical module, and a fixture for assembling a light source, an optical filter, and a lens disposed inside the package. . According to the present invention, an optical filter is disposed between an LD of a light source unit and an attached optical fiber and a light receiving unit is disposed below the optical filter, thereby allowing the optical path to pass through the optical filter to connect the light source unit to the optical fiber, The optical path between the PD-attached optical fiber of the light receiving unit is formed by the reflection. That is, the received light incident from the attached optical fiber to the bidirectional optical module passes through the lens through the ferrule into which the optical fiber is inserted, meets the optical filter inclined toward the bottom of the package, and reflects from the optical filter. The optical signal is received by focusing on the PD surface of the optical receiver. In addition, the signal light output from the LD assembled to the instrument is transmitted through the optical filter and then focused on the optical fiber fixed by the ferrule by the lens and output along the attached optical fiber, thereby transmitting the optical signal. Here, the wavelength of the received optical signal incident on the PD through the attached optical fiber to the PD and the wavelength of the transmitted optical signal output from the LD to the attached optical fiber are separated according to the reflection and transmission characteristics according to the wavelength of the optical filter. In other words, in the case of using an optical filter having a wavelength transmission characteristic of 1.3 µm wavelength / 1.55 µm wavelength, the bidirectional optical module of the present invention uses an LD having an output wavelength of 1.3 µm as a light source to provide an optical signal of 1.3 µm wavelength through a single attached optical fiber. It transmits and simultaneously receives an optical signal having a wavelength of 1.55 µm. In addition, when the polarizing reflection filter or the transflective filter having no wavelength selectivity is selected as the optical filter, transmission and reception of the same optical wavelength are possible. In addition, the bidirectional optical module according to the present invention is assembled on a ceramic substrate on which a light source unit and a light receiving unit are formed with an impedance matched strip line, and then connected to an external electronic circuit through a mini-DIL package. It has the advantage of being suitable for high speed optical signal transmission and reception of 1.25 and 2.5Gbps as well as 155 and 622Mbps optical signal transmission and reception.

In the bidirectional optical module of the present invention, after the assembly of the light source unit, the optical filter, and the lens is assembled into the mini-DIL package, the ferrule of the attached optical fiber is optically aligned with respect to the LD output light, and then fixed to the package by laser welding. It is manufactured in order to align and fix the light receiver at the bottom of the package while the incoming light is incident on the attached fiber. Therefore, the bidirectional optical module of the present invention is made of one light source unit, an optical filter, a lens, a light receiving unit, and a component of a device, and is assembled by laser welding once, so that the low cost and easy and fast demands of the optical subscriber network and the optical network for a computer are required. It satisfies the structure and manufacturing method of the bidirectional optical module that can be manufactured.

Hereinafter, with reference to the accompanying drawings, it will be described the structure, manufacturing method and operation of the bidirectional optical module of the present invention for simultaneously transmitting and receiving optical signals of different wavelengths. However, the following technical configuration is only an example of a preferred embodiment of the present invention and should not be construed as limiting or limiting the protection scope of the present invention.

2 shows a light source unit, an optical filter, a light receiving unit, a light source-optical filter-lens assembly mechanism, and an optical component layout of the present invention. The light source-optical filter-lens assembly mechanism 31 is composed of a light source assembly assembly area, an optical filter assembly inclined surface 32, and a lens insertion hole 33 near a diameter of 2mm as shown in the drawing, and manufactured by metal working. do. The angle θ1 formed between the light filter assembling surface 32 and the bottom surface is larger or smaller than 45 degrees. The light source block 21 is made of a ceramic material, and the LD 1 and the side-incident m-PD 40 are assembled thereon, and a strip line 23 for electrical connection between the optical device and the package pin 52 is provided. Each is arranged. The light receiving block 22 is made of a ceramic material, and an elliptic PD 41 and a preamplifier 4 of the present invention are assembled thereon, and a strip line for electrical connection between the optical device, the electronic device, and the package pin 52 is formed. 23) are arranged respectively. The strip line 23 has a width determined according to the thickness of the block to have a specific (eg, 50 Ohm) impedance for high speed transmission and reception of an electrical signal. The front surface of the wedge-shaped optical filter 44 is formed with a dichroic optical filter that transmits the wavelength of the transmitted light and reflects the wavelength of the received light, and an anti-reflective film is formed on the back of the wedge-shaped optical filter 44 that transmits both the transmitted and received light. The angle θ2 between the back sides is around 45 degrees. The lens 5 is a spherical or aspherical lens having a diameter of 2 mm and is inserted into the hole 33 and then bonded and fixed.

FIG. 3 is a small 8-pin mini-DIL package which is widely used for high speed optical communication. The package body 51 is made of ceramic and has a structure in which four electrical connection pins 52 are attached to each side. The front wall of the package has a through hole 54 around 2 mm in diameter, and a metal ring 53 for laser welding is attached around the hole to be used for fixing the attached fiber optic ferrule 8 later.

FIG. 4 shows Embodiment 1 of the present invention as the optical component of FIG. 2 is assembled inside the mini-DIL package of FIG. The assembly sequence of Embodiment 1 of Figure 4 is as follows. First, the light source block 21 and the light receiver block 22 are assembled, respectively. In the light source block 21, the light output height of the LD 1 and the light incident height of the side incident m-PD 40 manufactured in the optical waveguide type are the same, and the output light of the LD enters the optical waveguide of the m-PD. By inclining the incidence cross section of the m-PD to about 10 degrees, the light reflected from the cross section of the m-PD is prevented from entering the LD again to deteriorate the characteristics of the LD. Assemble the lens 5 to the light source-optical filter-lens assembly 31, attach the front surface of the wedge-shaped optical filter 44 to be parallel to the comb surface 32, and then assemble the lens shaft and LD (1). Align and assemble the light source block 21 so that the light output axis of the same. The assembled light source-optical filter-lens assembly mechanism 31 is aligned so that the axes of the lens, the LD, and the through-hole 54 coincide with each other, and then assembled into the mini-DIL package 51. The LD 1 of the light source unit and the m-PD 40 are electrically connected to the pins 52 through wire bonding via the strip line 23. The ferrule 8 is photoaligned while measuring the amount of light coupled to the attached optical fiber 9 by driving the LD 1, and then the ferrule 8, the ferrule holder 13, the ferrule holder 13, and the metal ring 54. Fix the gap with laser welding. The light receiving block 22 is inserted into the bottom of the package under the bevel 32 of the instrument 31 and is electrically connected to an external meter so as to detect the photocurrent of the elliptic PD 41. The photoreceptor block 22 is optically aligned using the photocurrent detected while the received light is incident through the attached optical fiber 9 and then fixed to the bottom of the package. The elliptical PD 41 and the preamplifier of the optical receiver are electrically connected to the pin 52 by wire bonding via the strip line 23. When assembling the optical component, the distance to the optical fiber ferrule 8 around the lens 5 and the wedge-shaped optical filter 44 are transmitted to the output surface of the LD 1 and reflected from the optical filter and the elliptical PD The magnification of the lens is used around 1 by adjusting the distance so that the distances to the incident surface of (41) are all similar. In addition, the assembly between the light source-light filter-lens assembly 31, the light source block 21, the light receiving block 22, and the mini-DIL package 51 is fixed using epoxy or solder. Except for the alignment of the optical fiber ferrule 8 and the alignment of the light receiving block 22, which require precise optical alignment, the axial alignment of the light source portion, the lens, and the through-hole is performed quickly and easily as a visual alignment using a low magnification microscope. The inside of the mini-DIL package 51 of FIG. 4 is completely sealed by the transparent window 7 by covering the upper part of the package in which the internal assembly is completed by electric welding. The operation of Example 1 of Figure 4 is as follows. Arrows between the lens 5, the LD 1, and the PD 41 indicate the traveling direction of the signal light. First, the output light of the LD 1 passes through the wedge-shaped optical filter 44 and is then focused and transmitted to the optical fiber ferrule 8 by the lens 5, and the light incident from the optical fiber ferrule passes through the lens and then the front surface of the optical filter. Is reflected by and focused on the light-receiving surface of the PD. Here, when adjusting the transmission / reflection wavelength characteristics of the dichroic optical filter formed on the front surface of the wedge-shaped optical filter, it is possible to obtain a bidirectional optical module which simultaneously performs transmission and reception of an optical signal of an arbitrary wavelength. For example, when using a dichroic optical filter with 1.3 μm wavelength transmission / 1.55 μm wavelength reflection, an optical signal having a wavelength of 1.55 μm can be received and 1.3 μm light without loss due to the insertion of an optical filter using LD having a 1.3 μm wavelength Signals can be sent at the same time. The front-elliptic PD of the optical fiber ferrule 8-lens 5-wedge optical filter 44, which occurs when the angle θ1 between the oblique surface 32 and the bottom surface of FIG. 2 is 45 degrees or smaller than 45 degrees. (41)-Front of wedge-shaped optical filter 44-Lens 5-Reverse path of the surface of the optical fiber ferrule 8 is formed to prevent the incoming light from traversing into the optical fiber ferrule. In addition, the angle θ2 between the front and rear surfaces of the wedge-shaped optical filter 44 is 45 degrees to prevent the back side from being perpendicular to the optical axis of the LD (1) so that the output light of the LD is reflected from the back side of the wedge-shaped optical filter to LD. To prevent deciding. Inclination of the optical fiber ferrule 8 by about 6 degrees prevents the output light of the LD from reflecting off the ferrule end face and feeding back to the LD.

FIG. 5A illustrates a change in optical cross-sectional shape according to a reception light path in an embodiment of the present invention, and FIG. 5B is a plan view of the elliptic PD 41 of the present invention. In (a), when the circular receiving light focused through the lens reflects from the inclined reflecting surface and reaches the light receiving part, the cross section of the receiving light changes to elliptical shape. When θ1 is 45 degrees, the long axis of the elliptical shape is 1.4 times larger than the shortening. In order to efficiently receive such elliptical reception light, in the present invention, as shown in (b), an elliptical PD 41 featuring an elliptical light receiving region 42 and an electrode 43 surrounding the light receiving region is provided in all embodiments. Apply.

FIG. 6 shows the light source-optical filter assembly 34 with the lens insert removed and the optical component arrangement of the wedge-shaped optical filter 44, which is difficult to process, with a conventional flat optical filter 6, An auxiliary optical filter 45 supported by the auxiliary optical filter support 24 is added to the elliptic PD 41 above 22.

FIG. 7 illustrates that the structure of FIG. 6 is applied to the mini-DIL package 51 and corresponds to Embodiment 2 of the present invention. The feature of this embodiment is that the lens 5 is inserted into and fixed to the through-hole 54 to simultaneously obtain a sealing effect inside the package as shown in the transparent window 7 of FIG. Assembly of this embodiment proceeds in the same order as in FIG. The front and rear surfaces of the flat panel optical filter 6 have the same dichroic optical filter and anti-reflective film, respectively, and are the same as the wedge shape. The assembling angle using the inclined surface is the same as that of the front surface of the optical filter of FIG. Do. The auxiliary optical filter 45 is a band-pass filter that transmits only the optical wavelength to be received by the optical receiver, and provides a function of selecting and receiving only one optical wavelength among a plurality of received light. For example, when the transmission wavelength band of the auxiliary optical filter is limited from 1.54 μm to 1.56 μm, only 1.55 μm signal light is received among the optical signals of 1.51 μm, 1.53 μm, 1.55 μm, and 1.57 μm wavelengths that are generally used in subscriber networks. do. The second embodiment functions in the same manner as the first embodiment except for the feature of subdivided optical wavelength selective reception by the auxiliary optical filter 45.

FIG. 8 shows an optical component arrangement diagram on the light source-optical filter assembly mechanism 34 as a light source unit in the case where the light source unit block 21 is divided into an LD block 25 and a double-sided m-PD block 26. , Corresponds to Example 3 of the present invention. The LD block 25 is made of a ceramic material in the same manner as the light source block 21, and the LD 1 is assembled at the upper center thereof. In FIG. 8, the double-sided m-PD block 26 is assembled by being turned upside down so that the surface on which the m-PD is attached on the upper side of the optical filter 8 faces downward, as indicated by the curved arrow in the figure. It functions to detect a part of the LD 1 light output reflected from the back of the filter 8. Here, when θ1 is 45 degrees without forming an antireflection film on the back of the optical filter, about 12% of the light output is incident on the m-PD (2), and the amount of light incident on the m-PD is formed by forming a reflective film. I can regulate it. Since the received light is reflected from the front side of the optical filter, it is not affected by the reflective film on the back side of the optical filter.

FIG. 9 shows the double-sided m-PD block 26 in detail, where (a) shows the front face to which the normal vertically-incident type m-PD (2) is attached, and (b) shows the pin 52 as the back face. The strip line 23 extends at both ends for electrical connection. The double-sided m-PD block 26 has strip lines 23 formed on both sides of the ceramic material, and the two-sided strip lines are electrically connected by the via holes 27.

Fig. 10 shows an optical component arrangement diagram on the light source-optical filter assembly mechanism 35 in the case where the light source block 21 is divided into the LD block 25 and the m-PD block 28 for cross section. Corresponds to Example 4. The form of the instrument 35 is characterized by having an inclined groove for accommodating the separate m-PD block 28 having a cross-sectional strip line pattern, when the m-PD block 28 is assembled on the inclined surface. Even if the rear light output of the light enters the m-PD (2) and partially reflects back, it acts to prevent feedback to the LD. 8 and 10, the optical axis alignment between the m-PD 2 and the LD 1 is performed by visual alignment through a low magnification microscope since the light receiving area of the m-PD is large and precise optical alignment is not required. Can be.

Fig. 11 shows a light source-optical filter assembly mechanism 36 and an optical component arrangement diagram for upwardly reflecting received light, which corresponds to Embodiment 5 of the present invention. For the upward reflection of the received light, the optical filter 6 is assembled with the front face upward as shown in the figure. Like θ1, the angle between the front face and the bottom face is larger or smaller than 45 degrees.

FIG. 11 is a view of the double-sided light receiving block 29 assembled to the rail on the top of the optical filter 6 assembled to the fixture 36 in FIG. 12. (a) is an elliptic PD (41) of the present invention as the front side, (b) is a preamplifier (4) is assembled as the rear side, and a plurality of strip lines (23) are arranged, and the front and rear are vias It is electrically connected to the hole 27.

FIG. 13 illustrates that the fixture 36 and the double-sided light receiving unit 29 of FIG. 11 are applied to the mini-DIL package 55 made of plastic, which corresponds to Embodiment 6 of the present invention. The body of the mini-DIL package 55 of FIG. 13 is changed from a conventional expensive ceramic material to a low-cost plastic material capable of compression injection. The laser welding tube (56) incorporating the role of the metal ring (53) and the tube penetrating the front wall of the package for the low-strength plastic body increases the mechanical strength of the laser welding section and at the same time the lens (5). By inserting and adhering, it also has the effect of sealing inside the package. The assembly of FIG. 13 is the same as that of FIG. 7 except that the assembly angle of the optical filter 6 is different. In the final step of assembling the optical receiver, the PD-side of the double-sided light receiver block 29 in the state where the received light is incident is present. It is turned upside down, and the light is aligned so that the amount of received light is maximum. Packages that have been assembled inside can be manufactured by covering them with a plastic lid, but the inside of the package can be filled with a material such as resin in consideration of the low sealing rate of plastics.

In order to prevent the front and rear light output of the LD 1 from scattering on the inner wall of the package and then entering the PD 41 to act as a noise source, in all embodiments of the present invention, the inner wall of the package is roughened or a light absorbing film is removed. Non-reflective surface treatment, such as forming.

Detailed embodiments of the present invention shown above are applied alone or in combination of several. For example, when the downward reflection structure of the received light of FIG. 6 and the upward reflection structure of FIG. 13 are simultaneously applied, as shown in FIG. 14, bidirectional light capable of simultaneously transmitting an optical signal of one wavelength and receiving an optical signal of two wavelengths may be used. The module is implemented. Example 7 of FIG. 14 is a light receiving unit for both sides and a light receiving unit for a single side under the down-reflecting optical filter after being assembled in the order of a down-reflecting optical filter, an up-reflecting optical filter, and an optical transmitting unit in the apparatus. The bride is assembled and aligned. In this case, when the reflection wavelength of each lower and upward optical filter is set to 1.54 μm and 1.52 μm or more, selective reception of optical signals of 1.55 μm and 1.53 μm is possible, respectively. Fine reflection wavelength adjustment, such as 1.54 μm and 1.52 μm, uses the longer reflection / transmission wavelength of the optical filter as the incident angle of light incident on the optical filter increases, so that the incident angle of incident light with respect to the same dichroic optical filter is used. By adjusting the 14 shows a state diagram in which the light source unit is separated and the cross-section m-PD block 28 is assembled on the inclined surface of the appliance.

The embodiments of the present invention described above are merely exemplary embodiments of the present invention, and do not represent all of the technical ideas of the present invention, and thus, various equivalents and modifications may be substituted for the present invention at the time of filing the present invention. It should be understood that there may be. Such modifications or changes of the present invention can be easily carried out by those skilled in the art, and therefore, the scope of the present invention should be regarded as including all such modifications or changes.

The present invention provides a structure and a manufacturing method for a bi-directional optical module of low cost, high reliability and high speed optical signal transmission and reception required in a single optical fiber distribution network of an optical subscriber network or a computer network. In particular, in the present invention, by using a single mini-DIL package and employing an assembly for the assembly of optical components, it provides a simple fabrication method that requires a small number of optical components and requires a minimum number of laser welding, thereby increasing the productivity of the optical module and This has the effect of lowering the price. In addition, it is possible to arrange the optical filter, a key optical component in a sealed package, thereby increasing the reliability of the optical module. With the Mini-DIL package, it adopts the optical transmission and reception block with strip line and provides the performance suitable for high speed optical signal transmission and reception of 1Gbps or more. Since the optical transmission and reception block are separated, they can crosstalk even for high speed optical signal transmission and reception. (crosstalk) is completely blocked.

Claims (18)

An optical module including a light source-optical filter-lens assembly, a light source block, a light receiving block, a lens, and an optical filter inside an 8-pin mini-DIL package. The light source-optical filter-lens assembly mechanism is formed with a light source unit assembly area, two pillars having an oblique surface formed at an angle greater than or equal to 45 degrees with the bottom surface for assembling the optical filter; The light source block is bonded to a ceramic or silicon substrate such that the LD and the side-incident m-PD are not parallel to the rear output surface of the LD and the front-side incident surface of the m-PD and are electrically connected between the optical device and the package pin. A plurality of impedance-matched strip lines are formed in the light source block assembly area of the appliance behind the optical filter; The optical filter is a wedge-shaped dichroic optical filter that reflects light above or below a specific light wavelength on the front surface, and an antireflection film is formed on the back side, and an angle between the front side and the rear side is about 45 degrees, and the front side is the slope of the instrument. Assembled in parallel with; The photoreceptor block has a PD and a preamplifier bonded to a ceramic or silicon substrate, and a plurality of impedance-matched strip lines for electrical connection between the optical device / electronic device and the package pin are formed. Is placed in; The lens is a spherical or aspherical surface having a diameter of about 2 mm and is inserted into and fixed in the lens insertion hole of the apparatus, and is disposed between the optical element of the LD and PD and the optical fiber ferrule; The mini-DIL package has a through hole formed in the front wall, and the inside of the package is sealed with a transparent window, and the outside is laser welded with an attached fiber ferrule inclined in cross section through a metal ring. Optical module. The method according to claim 1, The light source-optical filter-lens assembling device is a bidirectional optical module, characterized in that the lens assembly hole area is omitted and the lens is inserted into the package through hole and fixed. The method according to claim 1, The bidirectional optical module, characterized in that for replacing the PD with an elliptical PD having an elliptical light receiving area. The method according to claim 1, The bidirectional optical module, characterized in that for replacing the wedge-shaped optical filter with a flat plate optical filter having the same front and back optical filter characteristics. The method according to claim 1, The bidirectional optical module, characterized in that for adding an auxiliary optical filter having a band transmission characteristic using a support on the PD. The method according to claim 1, And dividing the light source unit block into an LD block and a double-sided m-PD block to assemble the m-PD block to an optical filter assembly column on the upper part of the optical filter so that the m-PD faces downward. The method according to claim 6, The double-sided m-PD block, the bi-directional optical module, characterized in that the m-PD is attached to one side and a plurality of strip lines are formed on both sides of the substrate and the electrical connection between the two-sided strip line as a via hole. The method according to claim 1, And dividing the light source block into an LD block and a cross-section m-PD block to assemble an m-PD block to an inclined surface of a groove formed in a light source assembly area of the apparatus. The method according to claim 6 or 8, The m-PD bidirectional optical module, characterized in that the vertical incidence type. The method according to claim 1, The bidirectional optical module, characterized in that for rotating the downward reflection optical filter 90 degrees so as to have an upward reflection characteristic. The method according to claim 10, Bidirectional optical module, characterized in that for assembling the two-sided light receiving unit block so that the PD is downward on the optical filter assembly column on the upper reflective optical filter. The method according to claim 11, The two-sided optical receiving block is a bi-directional optical module, characterized in that the PD and the pre-amplifier are assembled on both sides of the substrate, and a plurality of strip lines are formed, and the two-sided strip lines are electrically connected as via holes. The method according to claim 1, And a metal package having a similar structure or a tube for laser welding is replaced with a plastic package inserted into the front wall instead of the ceramic package as the mini-DIL package. The method according to claim 13, The bidirectional optical module characterized in that the inside of the plastic mini-DIL package is filled with a sealed resin. The method according to claim 1 or 13, Bi-directional optical module, characterized in that to coat the paint finish to roughly finish the inner wall of the mini-DIL package or to absorb the LD output light. The method according to claim 1, Instead of the dichroic optical filter formed on the front surface of the optical filter, by forming a semi-transmissive optical filter that transmits and reflects the amount of light around 50% irrespective of the wavelength, the optical signal of the same wavelength is simultaneously transmitted and received. Bidirectional optical module. The method according to claim 1, The optical filters having the two different reflection wavelength characteristics are disposed downward and upward, respectively, and the optical receiver block and the double-sided optical receiver block are disposed at the bottom and the upper part, respectively, to simultaneously receive optical signals having two different wavelengths. Bidirectional optical module, characterized in that. The method according to claim 16, And setting the reflection wavelengths of the two consecutive optical filters by adjusting an angle at which the optical filters are assembled.