KR102167838B1 - Optical modulator package for bi-directional data communication with low wavelength separation - Google Patents

Abstract

The present invention relates to an optical module package structure for bidirectional communication in which an optical transmission device for optical communication and an optical reception device are built in one package housing to simultaneously transmit and receive optical signals. In particular, the present invention relates to a structure of an optical module package for bidirectional communication using narrow wavelengths capable of separating two uplink and downlink optical signals having a wavelength interval of several nm, and the optical module package structure for bidirectional communication according to the present invention. Is equipped with a lens that converts laser light emitted from the laser diode chip into parallel light with a predetermined radiation angle in a light emitting optical device package including a laser diode chip such as a TO (transistor outline) type or a mini-flat type. The optical device package for light emission has a feature of being sealed with a flat window.

Description

Optical modulator package for bi-directional data communication with low wavelength separation}

The present invention relates to a structure of an optical module package for bi-directional communication, and in particular, a wavelength selective filter is inserted into a light-emitting device package optical transmission path through which parallel light is emitted and a light-receiving path in the form of parallel light. It relates to a package of an optical module for bidirectional communication to have a gap.

In recent years, optical communication using light as a medium for information transmission has become common for large-capacity information transmission and high-speed information communication. In recent years, it is possible to easily convert an electrical signal of 10 Gbps (giga bit per sec) into laser light by using a semiconductor laser diode chip of about 0.3 mm in width and length, respectively, and optical fiber using a semiconductor optical optical receiving device. The optical signal transmitted through can be easily converted into an electric signal. Light is an energy wave with very specific characteristics. In order for several lights present at the same time in a certain area to interact with each other, the targets of the light must have the same wavelength or have the same phase of light. Also, the direction of travel must be consistent. Therefore, the coherence between light is very low, and a wavelength division multiplexing (WDM) method of optical communication is preferred in which light having various wavelengths is simultaneously transmitted through one optical fiber using the characteristics of light. This WDM-type optical communication is a very economical communication method in that it reduces the cost of installing the optical fiber by allowing the sharing of optical fiber, which is a transmission medium of a signal. In order to use this wavelength multiplexing method, the line width of laser light used for communication must be very narrow. There are several methods of manufacturing such a narrow line width laser light source. One of them is a method of inserting a refractive index change grating into a laser diode chip. The laser diode chip manufactured by this method is used as a distributed feedbacl laser diode (DFB-LD). ). DFB-LD is emerging as the most important laser diode of the current wavelength multiplexing method because it easily performs 10Gbps high-speed communication. However, DFB-LD is used in a wavelength multiplexing method in which a wavelength gap of at least 20 nm exists as the wavelength changes by about 0.1 nm/℃ depending on the operating environment temperature, and the wavelength changes by about 9 nm at the operating environment temperature of -20 to 70°C. . In addition to this method, a laser light source having a narrow wavelength line width may be manufactured by injecting an external light source into a Fabry-Perot laser diode (FP-LD). This method does not determine the wavelength in the laser diode chip, but determines the wavelength externally, so there is an advantage in that there is no wavelength shift according to the temperature change of the laser diode chip. The wavelength multiplexing method of this external light source injection method can operate only at a low speed of 2.5 Gbps and cannot be used at an operation speed of 10 Gbps as well as 5 Gbps.

In recent years, FTTH (fiber to the home), which connects optical fibers to the inside of a communication subscriber's home, is becoming more common. In the FTTH method, which draws optical fibers to the inside of the communication subscriber's house and performs optical communication, upstream optical communication that generates an optical signal inside the communication subscriber's house and sends it to the base station for optical communication and converts the optical signal transmitted from the base station for optical communication into an electric signal. Downlink optical communication is required. As a method of performing the uplink and downlink optical communication, there is a method in which an optical fiber for processing an uplink optical signal and an optical fiber for processing a downlink optical signal are separately installed and used, but this method causes waste of optical fiber. Therefore, in recent years, a bidirectional optical communication method for transmitting an uplink optical signal and a downlink optical signal through a single fiber has been widely adopted. An optical receiving element that receives an optical signal transmitted downward through an optical fiber and converts it into an electrical signal, and an optical transmission element that converts an electrical signal into an optical signal and transmits it through an optical fiber, is integrated so that optical coupling occurs with one optical fiber. This module is collectively referred to as a BiDi module.

1 shows the structure of a conventional conventional BiDi module.

Hereinafter, in describing FIG. 1, the wavelength of light emitted from the TO-type optical transmission device 100 that is installed in the optical module housing 10 for bidirectional communication and transmits an optical signal upward to the optical fiber core 310 is 1550 nm, and the optical fiber The description will be made on the assumption that the wavelength of light transmitted downward from the core 310 and incident on the TO-type optical receiving device 200 is 1300 nm. In FIG. 1, the wavelength selective filter 500 having an inclination angle of 45° with respect to the incident laser light transmits a wavelength of 1550 nm by alternately depositing a dielectric thin film having a relatively high and low refractive index as a plurality of layers. A wavelength of 1300 nm can be manufactured to have wavelength selectivity to reflect. Therefore, the laser light having a wavelength of 1550 nm emitted from the TO-type optical transmission device 100 passes through the 45° wavelength selective filter 500 as it is to focus the optical signal light to the optical fiber core 310. The progress path is indicated by reference numeral 400. The downward light of 1300 nm wavelength emitted from the optical fiber core 310 enters the TO-type optical receiving device 200 by bending 90° in the direction of propagation in the 45° wavelength selective filter 500 reflecting the light of 1300 nm. Therefore, by using the optical module for bi-directional communication as shown in FIG. 1, the signal is simultaneously transmitted up and down using one optical fiber core 310. Conventional optical modules for two-way communication use a 45° wavelength selective filter 500 that has an angle of 45° to the direction of laser light, and selectively transmits or reflects light according to the wavelength. To decide.

In the 45° wavelength selective filter 500, the band of the transmitted or reflected wavelength varies according to the incident angle of light, and the polarization state of light incident to the 45° wavelength selective filter 500 Depending on the transmission or reflection wavelength band varies. Therefore, in order to stably transmit or reflect a specific wavelength, a band that transmits or reflects light stably regardless of the polarization and incident angle of the laser light incident to the 45° wavelength selective filter 500 is set and transmitted and The wavelength of the received laser light must be determined.

FIG. 2 shows a transmittance/reflectance curve according to a polarization state of light incident on a wavelength selective filter having an incident angle of 45° with respect to the optical axis of the advancing light. As shown in (a) of FIG. 2, in the case of a wavelength selective filter having a generally 45° incident angle, the transmission wavelength varies depending on the polarization state. In other words, even if they have the same wavelength, transmission and reflection are determined according to the polarization state. Therefore, in order to determine transmission and reflection according to the wavelength regardless of polarization, outside the wavelength shift band according to polarization as shown in Fig. 2(a). The wavelength must be determined, and the wavelength within this wavelength shifting band has the characteristic of reflecting part of the light to be completely transmitted according to the polarization, or the part of the light to be completely reflected may be transmitted, thereby interfering between the transmission and reception signals. As a result, the characteristics of the optical transmission module deteriorate. The wavelength shift band according to this polarization will be referred to as a guardband. Therefore, in the case of using the 45° wavelength selective filter (500), there is a wavelength gap of at least 20 nm or more between the transmission and reception wavelengths, and this wavelength gap cannot be used for optical communication. Decrease the efficiency of

The change in the transmission/reflection characteristics of the wavelength according to polarization completely disappears when the light enters the wavelength selective filter vertically, and the change in the transmission/reflection characteristics according to polarization occurs when the light is incident close to normal incidence at a small angle within 10°. It becomes insignificant. 2B is an example of a transmission reflection characteristic curve according to a wavelength when the angle between the vertical line of the wavelength selective filter and the incident laser light is 5°. When laser light is incident at a small angle of 5° to the line of the filter surface of the wavelength selective filter, the wavelength mobility of transmission/reflection according to polarization is less than 1 nm, and in the case of 45° incident, it is very small compared to the guardband of 20 nm. Have. Therefore, the smaller the angle between the repair line of the wavelength selective filter and the optical axis of the incident laser light, the narrower the wavelength can be separated.

The transmission/reflection characteristics according to the wavelength of the wavelength selective filter may vary depending on polarization and also vary according to the angle of incidence. The conventional optical module for bidirectional optical communication of FIG. 1 is directly focused to the optical fiber core 310 by a lens 150 attached to the TO-type optical transmission device 100, and the laser light emitted from the optical fiber core 310 is wavelength After entering the selective filter 500 at various angles of incidence, it is focused onto the photodiode chip 210 by the lens 250 of the TO-type optical receiving device 200. In this process, when the laser light emitted from the optical fiber core 310 enters the wavelength selective filter 500, the incident angle is not the same, so it is difficult to apply to a wavelength multiplexing method with a narrow wavelength interval.

This problem is caused by making the laser light emitted from the TO-type optical transmission device 100 into parallel light as shown in FIG. 3 and passing the wavelength selective filter 510 having an inclination angle of 3° to 10° to the incident laser light. The optical fiber-side lens 350 is used to focus on the optical fiber core 310, and the laser light emitted from the optical fiber-side lens 350 is converted into parallel light through the optical fiber-side lens 350, and then the wavelength selective filter 510 By reflecting and focusing on the photodiode 210 of the TO-type light receiving device 200, a narrow wavelength interval can be effectively separated.

Several problems arise in performing bidirectional communication of an optical signal having a narrow wavelength interval using a single optical fiber using the method shown in FIG. 3. The first problem is that DFB-LD (Distributed feedback laser diode), which is mainly used for TO type optical transmission device 100 in DWDM (Dense wavelength division multiplexing) system, separates narrow wavelength intervals by varying the wavelength according to the operating temperature. This is a problem in that there is a possibility that unwanted reflection may occur in the wavelength selective filter.

3, when the inclination angle of the wavelength selective filter is not 45° with respect to the laser light 460 incident on the wavelength selective filter 510, the light reflected from the wavelength selective filter 510 is a view between the optical transmission element and the optical fiber. It will not have a 90° angle to the furnace. In the optical module for bidirectional communication, it is preferable that the laser light emitted from the optical transmission device and the laser light incident on the optical receiving device are orthogonal to each other due to the structure. In the structure of FIG. 3, in order to make the laser light emitted from the optical transmitting device and the laser light incident to the optical receiving device orthogonal to each other, a reflective mirror 550 of FIG. 3 is further disposed to provide the laser light emitted from the optical transmitting device 100. The direction 400 of and the direction of laser light incident on the light receiving device 200 may be orthogonal to each other.

However, in this method, between the laser light reflected from the wavelength selective filter 510 and the laser light incident on the wavelength selective filter 510 after being converted to parallel light from the optical fiber core 310 and converted to the optical fiber side lens 350. Since the angle is not large, it becomes difficult to spatially separate the two lights. It is necessary to arrange the reflection mirror 550 in a region where the laser light traveling between the wavelength selective filter 510 and the optical fiber core 310 and the laser light reflected from the wavelength selective filter 510 are completely separated in space. The laser light 400 emitted from may be effectively focused to the optical fiber core 310, and the laser light emitted from the optical fiber core 310 may be effectively focused to the optical receiving device 200. There are various methods to spatially separate the laser light emitted from the optical transmission device 100 and the light reflected from the wavelength selective filter 510, but in each case, different secondary problems may occur. For example, 1) There is a method of arranging the angle of the wavelength-selective filter at a large angle with respect to the incident optical axis (for example, 20° to 45°), but at such a large angle, the guardband wavelength bandwidth according to polarization becomes wider, resulting in a narrow wavelength. Two-way optical communication using spaced laser light becomes difficult. 2) If the distance between the wavelength selective filter and the reflective mirror is increased, even when the optical axis of the optical transmission laser light and the angle of the wavelength selective filter are narrow, the optical transmission path and the light reflected from the wavelength selective filter can be spatially separated. However, this method has the disadvantage of increasing the size of the optical module for bidirectional communication.

In addition, when the diameter of the laser light emitted from the optical transmission device is large, in order to spatially separate the laser light emitted from the optical transmission device and the laser light reflected from the wavelength selective filter, a larger incident angle of the wavelength selective filter is required. The size of a module for bidirectional optical communication of a larger size is required.

4 shows a general structure of an optical transmission device that emits laser light having a characteristic of parallel light by using a conventional TO type optical transmission device. In the conventional TO type optical transmission device, the cap 140 to which the lens 150 is attached is attached to the stem 120 by electric resistance welding. At this time, the lower portion of the cap 140 is applied to the stem 120 with strong heat and pressure. A process of fusion is used, and at this time, mechanical deformation of the lower end of the cap 140 occurs. The mechanical deformation of the lower portion of the cap 140 that occurs when the cap 140 and the stem 120 are fused is very difficult to control. Due to the mechanical deformation of the lower portion of the cap 140, uncertainty in the distance and relative position between the laser diode chip 110 and the lens 150 occurs, and thus the laser light after passing through the lens 150 It becomes difficult to adjust the degree of parallelism and laser beam diameter, and to control the emission angle of the laser beam. In order to facilitate adjustment of the parallelism and emission angle of parallel light after passing through the lens 150 attached to the cap 140, it is advantageous if the distance between the lens 150 and the laser diode chip 110 increases. When the distance between the diode chip 110 and the lens 150 increases, the size of the laser light converted to parallel light increases, and thus the size of the optical module for bidirectional communication increases. Accordingly, it is difficult to effectively convert the laser light emitted from the optical transmission device into parallel light having a diameter of less than 0.6 mm by using the cap 140 to which the conventional lens 150 is attached.

Republic of Korea Patent Publication No. 10-1119491 (2012.02.16)

Accordingly, the present invention is to solve the problems of the prior art, and an object of the present invention is to make the optical axis of the optical transmitting device and the optical receiving device orthogonal, but it is possible to separate the laser light of the wavelength of narrow intervals and the operation speed is It is to provide an optical module structure for ultra-high speed and small-sized two-way communication that is 5Gbps or higher.

In the present invention, DFB-LD is used as a laser light source for ultra-high speed optical communication of 5 Gbps or higher and optical communication of a wavelength multiplexing method having a narrow wavelength interval of several nm, but a thermoelectric element is installed inside the TO-type optical transmission element. Then, a DFB-LD laser diode chip and a lens are placed on one side of the top of the thermoelectric element, and the laser light emitted from the DFB-LD is used as parallel light using the lens. In addition, the light emitting port of the TO-type optical transmission device employs a method of using a flat-type window. At this time, it is preferable that the flat window is made of a glass material, and it is preferable that anti-reflection coating is applied on both sides. In addition, in the present invention, the wavelength selective filter is arranged so that the optical axis is shifted from 3° to 10° with respect to the laser light incident through the wavelength selective filter, so that the separation wavelength interval according to polarization does not widen by more than 3 nm, It enables two-way communication using laser light.

In addition, in the present invention, the laser light emitted as parallel light from the optical transmission element is focused to the optical fiber core by the optical fiber side lens, and the laser light emitted from the optical fiber core is converted into parallel light by the optical fiber side lens, and the wavelength selective filter Let's proceed to. To minimize the volume of the two-way communication optical module, a reflection mirror is placed on the path of light emitted from the optical fiber and reflected by the wavelength selective filter, so that the optical signal reflected from the reflection mirror is orthogonal to the optical axis of the laser light emitted from the optical transmission element. After that, the laser light reflected from the reflective mirror is focused to the light receiving device. In the present invention, in order to minimize the volume of the optical module for bidirectional communication, the optical fiber side lens and the wavelength selective filter have an opening that is 1 to 2 times larger than the diameter of the light emitted from the optical transmission device, and a reflective mirror can be attached to one side. Arrange the equipment with a flat surface.

The optical module package structure for bi-directional communication according to the present invention uses DFB-LD, which is advantageous for high-speed communication and wavelength multiplexing, and enables ultra-high-speed communication of 5 Gbps or 10 Gbps, and the wavelength interval of up-and-down laser light is 1 nm to 2 nm or more. Since bidirectional communication is possible using an optical signal having a very narrow wavelength interval, an optical fiber can be used effectively. In addition, a thermoelectric element is mounted inside the optical transmission element to stabilize the wavelength of the optical transmission DFB-LD, enabling bi-directional communication at narrow wavelength intervals, and the laser diode chip and laser light emitted from the laser diode chip on the top of the thermoelectric element are transmitted. A lens that converts into parallel light is attached so that the laser light for optical transmission can be effectively converted into parallel light, and the diameter of the parallel light emitted from the laser diode chip can be effectively adjusted, making it possible to manufacture a micro-miniature optical module for two-way communication. In addition, the reflective mirror can be attached as closely as possible to the optical path between the laser diode chip and the optical fiber, making it possible to manufacture a micro optical module for bidirectional communication.

1 is a structural diagram of a conventional general BiDi module,
2A shows the transmittance according to the polarization state and wavelength of the incident light from the wavelength selective filter having an inclination angle of 45° with respect to the optical axis of the incident light,
2B shows the transmittance according to the polarization state and wavelength of the incident light from the wavelength selective filter having an inclination angle of 5° with respect to the optical axis of the incident light,
3 is an optical module for bidirectional communication when the wavelength selective filter has an inclination angle of 7° with respect to light incident on the wavelength selective filter;
4 is a conceptual diagram of a TO-type laser diode optical transmission device that does not include a conventional thermoelectric device,
5 is a conceptual diagram of a TO type laser diode optical transmission device having a flat window according to the present invention and including a thermoelectric element and a collimating lens therein;
6 is an embodiment of an optical module for bidirectional communication according to the present invention,
7 is another embodiment of an optical module for bidirectional communication according to the present invention,
8 is another embodiment of the optical module for bi-directional communication according to the present invention,
9 shows an embodiment of a metal fixture having a reflective mirror mounted on one side of the present invention, a space through which an optical fiber side lens is pressed, and a through hole through which laser light passes.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 shows an optical transmission device that emits parallel light having a small diameter and excellent parallelism according to an embodiment of the present invention. At this time, the diameter of the laser beam is defined as the distance at which the intensity of the laser beam becomes 1/e^2. In the embodiment of the present invention, the thermoelectric element 170 is disposed on the stem 120 of the TO package, and the DFB-LD laser diode chip 110 and the laser diode chip 100 are placed on the thermoelectric element 170. A lens 180 for converting the emitted laser light into parallel light is disposed. The lens 180 is fixedly disposed with epoxy or solder, and the attachment of the lens 180 by epoxy or solder is not a method of applying an impact, and the divergence point of the laser diode chip 110 is disposed at the focal length of the lens 180. Very precise optical alignment is possible, and a precise lens 180 can be fixed so that the deformation of the fixed position is small after the precise alignment of the lens 180. In the method of fixing the lens 180 with epoxy or solder, since the position of the lens 180 can be controlled very precisely, characteristics of parallel light can be easily obtained even when a lens having a short focal length is used. When a lens with a short focal length is used, the diameter of the laser light converted to parallel light is reduced, so that the light traveling between the wavelength selective filter and the optical fiber and the light reflected from the wavelength selective filter can be easily separated locally. It is possible to manufacture a small optical module for bidirectional communication. In the present invention, since the temperature of the laser diode chip 110 is constant irrespective of the external environmental temperature by the thermoelectric element 170 as shown in FIG. 5, the oscillation wavelength of the laser diode chip 110 is changed according to the external environmental temperature. Since it does not change, two-way optical communication can be achieved using laser light with a narrow wavelength interval.

6 is an embodiment of an optical module for bidirectional communication according to the present invention.

In order to reduce the size of the module for bidirectional optical communication, a reflective mirror 550 for sending the laser light reflected by the wavelength selective filter 510 to the optical receiving device 200 starting from the optical fiber core 310 is a wavelength selective filter 510 ) And the optical axis of the laser light traveling between the optical fiber core 310 should be as close as possible. In general, the optical fiber-side lens 350 for converting the laser light emitted from the optical fiber core 310 into parallel light has a lens portion diameter of about 1.5 mm, and an outer diameter of a metal appliance including the lens is about 3 mm. As an example, as shown in FIG. 6, when the diameter of the laser beam is 0.6 mm and the reflection mirror 550 is to be disposed on the side of the optical fiber side lens 350, the light reflected from the wavelength selective filter 510 is reflected in the reflection mirror 550 When reaching ), the movement distance of the reflected light must be at least 2.1mm, so that the reflection of the laser light can occur by the reflection mirror 550 disposed on the side of the optical fiber side lens 350. For example, when the wavelength selective filter 510 is inclined about 7° with respect to the incident light, the distance from the wavelength selective filter 510 to the reflection mirror should be at least 8 mm, as shown in FIG. The size of the module housing 10 is about 13 mm. In order to minimize the size of the optical module housing 10 for bidirectional communication, it is preferable that the reflective mirror is arranged as close as possible to the path of the laser light.

As shown in FIG. 7, a through hole is drilled in the metal fixture 600 to which the reflective mirror 550 is attached, and a flat surface for attaching the reflective mirror 550 to the outer periphery of the metal fixture 600 is formed. After processing, the laser light passing between the wavelength selective filter 510 and the optical fiber core 310 passes through the through hole of the metal fixture 600, and a reflective mirror ( 550) can be adopted. At this time, it is preferable that the through hole of the metal fixture 600 is slightly larger than the diameter of the laser light, and the diameter of the through hole is preferably 1 to 2 times the diameter of the laser beam. This is because when the diameter of the through hole is smaller than the diameter of the laser beam, light to pass through may be reflected by the metal fixture. In addition, if the axis of the through hole and the axis of the optical fiber side do not coincide, the laser light may be blocked by metal objects. Therefore, the diameter of the through hole is preferably larger than the diameter of the laser light, but if the diameter of the through hole is too large, there is a disadvantage that the reflective mirror 550 is distant from the optical axis of the laser light. Therefore, the method of adjusting the diameter of the through hole to be about 1.1 to 1.5 times larger than the diameter of the laser light can effectively reduce the optical loss due to errors such as optical alignment, and at the same time bring the reflective mirror closest to the optical axis. In the present invention, the laser light has a Gaussian beam intensity shape, and the diameter of the laser beam is given as the distance between the points 1/e^2 falling from the maximum intensity of the light. In the embodiment shown in FIG. 7, the distance from the wavelength selective filter 510 to the reflective mirror 550 is reduced to 4.7 mm, and the length of the optical module housing 10 for bidirectional communication is reduced to 11.9 mm.

On the other hand, when the metal fixture 600 and the optical fiber side lens 350 are spaced apart as shown in FIG. 7, it is difficult to precisely match the axis of the through hole of the metal fixture 600 with the central optical axis of the optical fiber side lens 350. have.

This problem is caused by securing a space in which the optical fiber side lens 350 can be inserted into the metal fixture 610 as shown in FIG. 8 and manufacturing the optical fiber side lens 350 integrally with the metal fixture 610 to prevent optical alignment. It is possible to easily match the optical axis of the through hole of the metal fixture 610 with the optical axis of the optical fiber side lens 350. Since the metal fixture 610 is manufactured in a cylindrical shape, it is very easy to make the through-hole of the metal fixture 610 and the axis of the space in which the optical fiber side lens 350 is inserted coincide with each other by lathe work. Therefore, the diameter of the space portion of the metal fixture 610 into which the optical fiber side lens 350 is to be inserted is made 5 to 30 μm larger than the diameter of the optical fiber side lens 350, but the through hole and the axis of the metal device 610 are aligned. When the optical fiber side lens 350 is inserted after fabrication, the optical axis of the optical fiber side lens 350 and the optical axis of the metal fixture 610 can be very easily matched. As shown in FIG. 8, when the optical fiber side lens 350 is inserted into a metal fixture 610 used as a support for the reflective mirror 550, the axis of the through hole of the optical fiber side lens 350 and the metal fixture 610 is Not only can it be easily aligned, but also the size of the optical module housing 10 for bidirectional communication can be further reduced. In the embodiment as shown in FIG. 8, the distance from the wavelength selective filter 510 to the reflective mirror 550 is 4.7 mm as in the structure of FIG. 7, but the size of the optical module housing 10 for bidirectional communication may be reduced to 10.3 mm.

9 shows a state in which the reflective mirror 550 is mounted on a metal fixture 610 having a space in which the optical fiber side lens can be mounted and a flat surface to which the reflective mirror can be attached.

Therefore, in an optical module for bi-directional communication that uses up/down optical signals with a narrow wavelength interval of several nm, a laser diode chip for optical transmission and a lens that converts the divergent light emitted from the laser diode chip into parallel light are placed on the thermoelectric element to transmit light. Credit: A reflective mirror is attached to one side of the manufactured metal fixture by minimizing the diameter of the collimated light and inserting the optical fiber side lens into a metal fixture with a through hole, and radiating from the optical fiber through the reflective mirror. The optical module structure for bidirectional communication, which is converted into parallel light by a lens and focuses the received light signal reflected by the wavelength selective filter to the light receiving element, stabilizes the oscillation wavelength of the laser diode chip for optical transmission and converts it into parallel light. For this reason, wavelength separation is easy in the wavelength selective filter, and the volume is small, so the utilization is very high.

The present invention is not limited to the above-described embodiments, and various modifications and variations within the scope of the technical idea of the present invention and the scope of the claims to be described below by those of ordinary skill in the technical field to which the present invention belongs. Of course this can be done.

10: Optical module housing for bidirectional communication
100: optical transmission device with a lens attached to the cap
101: TO type optical transmission device
110: laser diode chip
120: Stem of the TO type optical transmission device package
125: electrode pin of the TO-type optical transmission device
130: stem header of the TO-type optical transmission device
140: TO-type optical transmission device cap
150: Lens attached to the cap of the TO-type optical transmission device
170: thermoelectric element
180: collimating lens
190: flat-type window
185: 45 degree reflective mirror
200: TO type optical receiving device
210: photodiode chip
250: Lens attached to the cap of the TO-type optical transmission device
300: optical fiber
310: fiber core
350: optical fiber side lens
400: path of laser light from the optical transmission device to the optical fiber
450: The path of laser light emitted from the optical fiber and proceeds to the wavelength selective filter
460: Path of laser light emitted from the optical fiber and reflected from the wavelength selective filter
500: Wavelength selective filter having an inclination angle of 45° to the incident laser light
510: wavelength selective filter having an inclination angle of 3° to 10° with respect to the incident laser light
550: reflective mirror
600: Metal fixtures with through-holes and flat slopes formed
610: a metal fixture into which the optical fiber side lens

Claims (12)

In the optical module package structure for bi-directional communication having an optical transmission device, an optical receiving device, and a wavelength selective filter for determining transmission and reflection according to a wavelength,
In the optical transmission device having a flat-panel window, a lens for converting the laser light into parallel light is disposed on the path of the laser light having the characteristic of the divergent light emitted from the laser diode chip, and is parallel by the lens. The laser light converted to light passes through the wavelength selective filter and is focused into the optical fiber by the optical fiber lens.
The optical signal emitted from the optical fiber is converted into parallel light by the optical fiber side lens, is reflected by a wavelength selective filter, is reflected again by a reflective mirror, and is focused to the optical receiving device,
The optical transmission laser diode chip included in the optical transmission device includes a distributed feedbacl laser diode (DFB-LD) so that the wavelength of the laser light is controlled by a thermoelectric element,
The wavelength selective filter is an optical module package structure for bidirectional communication, characterized in that the incident surface is inclined by 3° to 10° with respect to the optical axis of the incident laser light.
The method according to claim 1,
The optical transmission device is configured to include a laser diode chip and a collimating lens, a window for airtightness of the optical transmission device is configured as a flat window, and the laser diode chip and the collimating lens are disposed on the thermoelectric device. Optical module package structure for two-way communication.
The method according to claim 2,
The optical transmission device further comprises a laser diode chip and a 45° reflective mirror disposed on the optical path of the hermetic flat window.
The method according to claim 1,
The optical module package structure for bidirectional communication, characterized in that the optical transmission device is a TO can type package.
delete The method according to claim 1,
After being diverted from the optical fiber and converted into parallel light by the optical fiber side lens, the light of the wavelength reflected by the wavelength selective filter is reflected again by the reflection mirror, and the path of the laser light reflected by the reflection mirror is Optical module package structure for bi-directional communication, characterized in that after being perpendicular to the path of the laser light passing through the lens and proceeding to the wavelength selective filter, it is focused to an optical receiving device.
The method according to claim 1,
The optical fiber-side lens is installed by being inserted into a cylindrical metal fixture processed obliquely and flat so that one side has an incidence angle of a predetermined angle with respect to the incident laser light,
The cylindrical metal fixture has an opening through which light passes, and the opening formed in the cylindrical metal fixture has a size of 1 to 2 times the diameter of light emitted from the optical transmission device. Communication optical module package structure.
The method of claim 7,
An optical module package structure for bidirectional communication, characterized in that the opening formed in the cylindrical metal fixture is made to be 1.1 to 1.5 times the diameter of light emitted from the optical transmission device.
The method of claim 7,
An optical module package for bi-directional communication, characterized in that a reflective mirror is attached to the flat surface of the metal fixture, which is emanated from the optical fiber, passes through the optical fiber side lens, and then reflects the laser light reflected by a wavelength selective filter again. rescue.
The method of claim 9,
The reflective mirror is manufactured by coating a metal thin film on a substrate made of any one of glass, quartz, and silicon so that a mirror surface is formed on the surface thereof.
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