WO2022025646A1

WO2022025646A1 - Optical transmission and reception module capable of distinguishing wavelength of 40 nm by using polarizing plate

Info

Publication number: WO2022025646A1
Application number: PCT/KR2021/009838
Authority: WO
Inventors: 박일하; 서준영
Original assignee: 주식회사 지오스테크놀러지
Priority date: 2020-07-31
Filing date: 2021-07-28
Publication date: 2022-02-03

Abstract

Disclosed is an optical transmission and reception module capable of distinguishing a wavelength of 40 nm by using a polarizing plate. According to one embodiment of the present invention, provided is the optical transmission and reception module which is powerful at a low temperature, can separate optical signals into short wavelength intervals, and can be manufactured at a low production cost.

Description

Optical transmission/reception module capable of distinguishing a wavelength of 40 NM by using a polarizing plate

The present invention relates to an optical transmission/reception module capable of distinguishing a wavelength of 40 nm by using a polarizing plate.

The content described in this section merely provides background information on an embodiment of the present invention and does not constitute the prior art.

In general, the optical transmission/reception module refers to a module that accommodates various optical communication functions in one package to enable connection with an optical fiber. The optical transceiver module generally includes an optical transmitter using a laser diode as a light source that consumes less power and can be used over a long distance, and an optical receiver that performs optical communication using a photodiode.

The optical transmit/receive module basically includes an optical transmitter, an optical receiver, and a receptacle. In addition, in order to prevent the characteristics of the laser diode from being unstable due to reflected noise, an isolator is mounted in the optical transmission/reception module.

Since such an optical transceiver module can be used in various devices, it can be exposed to various environments. The optical transceiver module may be exposed to a high temperature of 60°C or higher, or may be exposed to a low temperature of -20°C or lower.

The conventional optical transceiver module has a strong characteristic in a high temperature environment, but the optical characteristic is significantly deteriorated in a low temperature environment of -20°C or less. Conventional optical transmission/reception modules that maintain optical characteristics in a low-temperature environment have a problem of being difficult to be distributed because they are quite expensive. Accordingly, there is a demand for an optical transmission/reception module that is inexpensive and has excellent optical characteristics at a low temperature.

In addition, in order to prevent the light to be irradiated to the outside from flowing back into the light source in the conventional optical transceiver module, an optical isolator is included therein. However, the optical isolator is a fairly expensive component that accounts for about 30% of the cost of the optical transmission/reception module, and occupies a significant proportion in the cost increase of the optical transmission/reception module. In addition, the optical isolator occupies a certain proportion in the optical transmission/reception module spatially, causing spatial and cost inefficiency of the optical transmission/reception module.

An embodiment of the present invention has an object to provide an optical transmission/reception module capable of separating optical signals at short wavelength intervals while being robust at low temperatures.

Another object of the present invention is to provide an optical transmission/reception module that can be manufactured at low cost while being robust at low temperatures.

According to one aspect of the present invention, a light source unit for irradiating linearly polarized light and a polarizing filter that passes only light having a preset polarization direction, passes light of a preset wavelength band but reflects light of the remaining wavelength band, and the light source unit; An antireflection unit that is disposed on the optical path of the polarizing filter and passes only light traveling through the polarizing filter, a ferrule that outputs light that has passed through the polarizing filter to the outside, and a wavelength band other than a preset wavelength band output from the outside It provides an optical transmission/reception module comprising a receiving end for receiving the light reflected from the polarization filter.

According to one aspect of the present invention, the anti-reflection unit is characterized in that it includes a polarizing plate that passes only light in a preset polarization direction and a quarter-wave plate that converts the polarization direction of incident light by 45°.

According to one aspect of the present invention, the polarizing plate is characterized in that it is disposed in front of the 1/4 wave plate on the light path irradiated from the light source unit.

According to one aspect of the present invention, the polarizing plate is characterized in that the light irradiated from the light source unit passes, but does not pass the light passing through the 1/4 wave plate.

As described above, according to one aspect of the present invention, there are advantages in that a relatively inexpensive device can be used while being robust to a low temperature, and an optical signal can be separated at a short wavelength interval.

In addition, according to one aspect of the present invention, it can be manufactured at a low cost using a relatively inexpensive device, and has an advantage of being robust at low temperature.

1 is a diagram illustrating an optical transmission/reception module according to an embodiment of the present invention.

2 is a cross-sectional view of an optical transmitter, an optical receiver and a receptacle according to a first embodiment of the present invention.

3 and 4 are graphs showing transmittance according to wavelength of the filter according to the first embodiment of the present invention and the conventional filter.

5 is a cross-sectional view of an optical transmitter, an optical receiver and a receptacle according to a second embodiment of the present invention.

6 is a view showing an anti-reflection unit according to a second embodiment of the present invention.

7 is a view showing a heater unit according to an embodiment of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements.

Terms such as first, second, A, and B may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being “connected” or “connected” to another component, it may be directly connected or connected to the other component, but it is understood that other components may exist in between. it should be On the other hand, when a certain element is referred to as being “directly connected” or “directly connected” to another element, it should be understood that no other element is present in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. It should be understood that terms such as “comprise” or “have” in the present application do not preclude in advance the possibility of the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. .

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, each configuration, process, process or method included in each embodiment of the present invention may be shared within a range that does not technically contradict each other.

Referring to FIG. 1 , an optical transceiving module 100 according to an embodiment of the present invention includes an optical transmitter 110 , an optical receiver 120 , a receptacle 130 , and a heater unit 140 .

The optical transmitter 110 irradiates linearly polarized light of a preset wavelength band. The optical transmitter 110 generates and irradiates light to be transmitted to another optical transmission/reception module. At this time, the irradiated light has a preset wavelength band by a WDM (Wavelength Division Multiplexing) method, is linearly polarized in a constant polarization direction, and is irradiated.

The optical receiver 120 is positioned in a direction perpendicular to the optical transmitter 110 and receives light irradiated from another optical transceiving module. Linearly polarized light of a wavelength band different from a preset wavelength band is irradiated from another optical transmission/reception module. Light irradiated from other optical transmission/reception modules is linearly polarized and has a wavelength band different from a preset wavelength band. Accordingly, the corresponding light proceeds not to the optical transmitter 110 but to the optical receiver 120 positioned in a direction perpendicular to the optical transmitter 110 . The optical receiver 120 receives incident light.

The receptacle 130 outputs the light irradiated from the optical transmitter 110 to the outside, and receives the light irradiated from the outside. The receptacle 130 includes a stub therein, so that the light irradiated from the optical transmitter 110 can be output through a preset path. In addition, the receptacle 130 allows light irradiated from other optical transmission/reception modules to be introduced into a preset path.

The heater unit 140 applies heat to the optical transmitter 110 so that the optical transmitter 110 can operate smoothly even at a low temperature. The wavelength of the light irradiated from the optical transmitter 110 is shifted according to the temperature. In addition, the light source included in the optical transmitter may operate in a wide temperature range of -40°C to 85°C, but the light source for operating in such a wide temperature range is quite expensive. Accordingly, a light source having a narrow temperature range for operation is used in an optical transmitter that is relatively inexpensive and widely used. In particular, such a light source has significantly lower operating performance at a lower temperature than at a higher temperature. To prevent this, the heater unit 140 is connected to the optical transmitter 110 in the opposite direction to which light is irradiated from the optical transmitter 110 . The heater unit 140 may be connected to the optical transmitter 110 by a separate adhesive material such as solder, or may be structurally directly connected to the optical transmitter 110 by using a connection medium such as a screw. The heater unit 140 is connected to the optical transmitter 110 to apply heat to the optical transmitter 110 . Since it is directly or indirectly connected to the optical transmitter 110 and is connected in close proximity to a portion irradiating light, the heater unit 140 does not require a separate excessive space for arrangement and is a high-cost light source having high efficiency. Even if it is not included, the operating performance of the optical transmitter 110 may be improved.

In order to secure the convenience of manufacturing and the convenience of connection with the optical transmitter 110 , the heater unit 140 may be implemented as a flexible printed circuit board (FPCB). The heater unit 140 is implemented as a flexible printed circuit board, and includes a means for heat generation therein, and applies heat to the optical transmitter 110 . A specific structure of the heater unit 140 will be described later with reference to FIG. 7 .

The optical transmitter 110 includes a stem 210 , a photodiode 212 , a light source 214 , a lens 216 , and a housing 218 .

The stem 210 supports components within the optical transmitter 110 . The stem 210 is disposed at the lower end of the optical transmitter 110 (in the +x-axis direction in FIG. 2 ), and supports the components in the optical transmitter 110 . The stem 210 is implemented with a material with high thermal conductivity, and transfers heat generated from the heater unit disposed at the lower end of the optical transmitter 110 (in the +x-axis direction in FIG. 2 ) to the optical transmitter 110 , The heat generated in (110) is discharged to the outside.

The photodiode 212 receives a portion of the light irradiated from the light source 214 and monitors the light irradiated from the light source 214 . The photodiode 212 is disposed on the submount 213 positioned on the stem 210 to receive a portion of the light to be irradiated. The photodiode 212 senses the received light to monitor the light to be irradiated.

The light source 214 irradiates linearly polarized light of a preset wavelength band.

The light source 214 irradiates light polarized in one direction. Here, the light irradiated from the light source 214 has a polarization direction having a phase difference of 90° from a polarization direction passed by a polarization filter 234 to be described later. Since the irradiated light has a polarization direction in the corresponding direction, it can pass through the polarization filter 234 without loss due to other components passing through and incident on the polarization filter 234 . Here, light has P polarization and S polarization, and the P polarization component is generally the polarization direction of the light. That is, the light irradiated from the light source 214 is irradiated so that the P polarization direction has a 90° phase difference from the polarization direction that the polarization filter 234 passes.

The light source 214 irradiates light of a preset wavelength band. Here, the light of the preset wavelength band is a wavelength band through which the polarization filter 234 passes. The light source 214 irradiates light of a preset wavelength band so that the light can pass through the polarization filter 234 and be irradiated to the outside of the receptacle 130 .

Here, the light source 214 may be implemented as a laser diode (LD), but is not limited thereto.

The lens 216 is disposed in front (-x-axis direction) on the path on which the light is irradiated from the light source 214 to focus the light irradiated from the light source 214 . The lens 216 focuses the light irradiated from the light source 214 so that most of the irradiated light is not dispersed and is incident on the half-wave plate 230 to be described later.

The housing 218 is disposed outside the optical transmitter 110 , and protects the internal configuration of the optical transmitter 110 from external forces, and prevents the internal configuration of the optical transmitter 110 from escaping to the outside.

The optical receiver 120 includes an optical filter 220 , a lens 222 , a photodiode 224 and a stem 226 .

The optical filter 220 is disposed at the front end on the optical path incident to the optical receiver 120 to filter clutter other than the light irradiated from other optical transmission/reception modules.

The lens 222 is disposed behind (on the optical path) (+y-axis direction) of the optical filter 220 to focus the light passing through the optical filter 220 to the photodiode 224 .

The photodiode 224 receives light that is output from another optical transmission/reception module and flows into the optical transmission/reception module 100 . The photodiode 224 receives and senses the light output from the other optical transceiving module, thereby receiving a signal transmitted by the other optical transceiving module.

The stem 226 supports the internal components of the optical receiver 120 , particularly the photodiode 224 , and radiates heat generated from the photodiode 224 to the outside.

The half-wave plate 230 is disposed in front (-x-axis direction) of the optical transmitter 110 on the optical path, and sets the polarization direction of the light irradiated from the optical transmitter 110 in a certain direction (eg, clockwise). direction) by 45°.

The optical isolator 232 is disposed in front (-x-axis direction) of the half-wave plate 230 on the optical path, and passes the light passing through the half-wave plate 230 but does not pass the light incident from the polarizing filter 234 . . The optical isolator 232 includes a first polarizer that passes only light having a polarization direction rotated by 45° in a predetermined direction by the half-wave plate 230 at an end close to the optical transmitter 110 . On the other hand, the optical isolator 232 includes a second polarizer that passes only light having a polarization direction rotated by 45° in a predetermined direction from the polarization direction of the aforementioned polarizer at the other end (end close to the polarizing filter 234). do. The optical isolator 232 includes a configuration that rotates the polarization direction of the light introduced between both polarizers by 45° in a constant direction again. Accordingly, the light irradiated from the optical transmitter 110 to the optical isolator 232 passes through the first polarizer, passes the above-described configuration, and the polarization direction is rotated by 45° (in a constant direction), and passes through the second polarizer. do. On the other hand, the light entering the second polarizer of the optical isolator passes through the above-described configuration and the polarization direction is rotated by 45° (in a constant direction), and the difference between the first polarizer and the polarization direction of 90° is reduced by the rotation of the polarization direction. is generated and does not pass through the first polarizer.

The light output from the optical transmitter 110 passes through the half-wave plate 230 and the optical isolator 232 and proceeds with the polarization axis rotated 90° in a certain direction.

The polarizing filter 234 is disposed in front of the optical isolator 232 on the optical path, so that the light passing through the optical isolator 232 is passed, but the light entering through the receptacle 130 is reflected. The polarization filter 234 reflects only light in a preset polarization direction and filters light in other directions. At the same time, the polarizing filter 234 passes light of a preset wavelength band, but reflects light other than the preset wavelength band (adjacent wavelength band). The polarization direction passed by the polarization filter 234 corresponds to a direction having a difference of 90° from the polarization direction of the light irradiated from the light transmitter 110 , in particular, the light source 214 . According to this feature, the polarization filter 234 passes only a polarization component (P polarization) that matches the polarization direction of light, and does not pass a polarization component (S polarization) that is perpendicular to the polarization direction of light. Since the (transmission) light irradiated from the optical transmitter 110 has a preset wavelength band, the P polarization component of the preset wavelength band passes through the polarization filter 234 and proceeds to the receptacle 130 . Conversely, the light introduced from the outside into the receptacle 130 has the same polarization component (P polarization) and is output from other optical transceiving modules, while preventing interference with the light output from the optical transceiving module 100 in a wavelength band. It has a wavelength band adjacent to this preset wavelength band. According to this characteristic, (received) light that flows into the polarization filter 234 through the receptacle 130 from the outside is reflected from the polarization filter 234 to the optical receiver 120 .

As the polarization filter 234 reflects only light in a preset polarization direction, the optical transmission/reception module 100 may transmit/receive light having a narrower wavelength than that of a conventional optical transmission/reception module. Conventionally, light was mainly transmitted and received using a wavelength band having a wavelength of 60 nm. For example, if the transmitted light is light having a wavelength band of 1270 to 1330 nm, the received light is 1210 to 1270 nm or light having a wavelength band of 1330 to 1390 nm is used. Due to the characteristics of the conventional optical transceiver module (particularly, the separation filter), the light in the 40nm wavelength band could be distinguished. However, in the process of transmitting and receiving light, a shift in wavelength due to a change in temperature may occur about 6 to 6.5 nm. Therefore, in order to minimize interference, the transmit/receive light must have a wavelength of 60 nm. However, since the optical transmission/reception module 100 includes the polarization filter 234 , it is possible to prevent interference of transmitted/received light even if it has a wavelength width of 40 nm which is narrower than the conventional wavelength width. This can be confirmed from the graphs of FIGS. 3 and 4 .

Referring to FIG. 3 , since the polarization filter 234 passes only light in a specific polarization direction, an adverse effect due to an afterimage in an adjacent wavelength band is minimized. Accordingly, for example, if the polarizing filter 234 is a filter that passes light having a wavelength band of 1270 to 1310 nm, the transmittance starts to decrease rapidly from the 1280 nm band, and the transmittance converges to almost 0% within 1300 nm. do. For this reason, even in consideration of shift due to temperature change, even if the optical transmission/reception module 100 including the polarization filter 234 has a wavelength of 40 nm, interference of transmission/reception light can be prevented.

On the other hand, referring to FIG. 4 , it can be seen that the transmittance of the conventional polarizing filter starts to gradually decrease from the band of 1290 nm, and the transmittance converges to almost 0% only at around 1320 nm. Therefore, considering the shift due to temperature change in the conventional polarizing filter, the optical transmission/reception module including the conventional polarizing filter must have a wavelength of at least 60 nm to prevent interference of transmitted/received light.

Referring again to FIG. 2 , the light reflection unit 236 is disposed vertically below the polarization filter 234 (in a direction opposite to the direction in which light is reflected from the polarization filter, in the -y-axis direction). The light reflection unit 236 is a structure formed in a housing in which the light isolator 232 and the polarization filter 234 are disposed, and changes the direction of light incident thereon. The light reflection unit 236 may have a structure that is concave vertically below the polarization filter 234 or a structure that protrudes convexly. Theoretically, the light output from the optical transmitter 110 and incident on the polarization filter 234 should completely pass through the polarization filter 234 , but in reality, the light output from the optical transmitter 110 uses a very small proportion of the polarization filter. (234) is reflected in the case occurs. If the light reflection unit 236 does not exist, the light reflected from the polarization filter 234 is reflected by the housing and flows into the optical receiver 120 . When the light reflected from the polarization filter 234 flows into the optical receiver 120, distortion of the result occurs. To prevent this, the light reflection unit 236 changes the path of the reflected light (unintentionally) from the vertically downward direction of the polarizing filter 234 to the vertical downward direction. The light whose path is changed by the light reflection unit 236 does not enter the optical receiver 120 .

The receptacle 130 includes a stub 240 and a housing 242 .

The stub 240 is disposed in the housing 242 , outputs the light output from the optical transmitter 110 to the outside, and transmits the light introduced from the outside to the polarization filter 234 .

The housing 242 includes the stub 240 therein, and protects the stub 240 from external force and fixes the stub 240 .

Referring to FIG. 5 , the optical transmitter 110 includes a stem 510 , a photodiode 512 , a light source 514 , a lens 516 , and a housing 518 .

The stem 510 supports components within the optical transmitter 110 . The stem 510 is disposed at the lower end of the optical transmitter 110 (in the +x-axis direction in FIG. 5 ), and supports components in the optical transmitter 110 . The stem 510 is implemented with a material having high thermal conductivity, and transfers heat generated from the heater unit disposed at the lower end of the optical transmitter 110 (in the +x-axis direction in FIG. 5 ) to the optical transmitter 110 , Heat generated in 110 is discharged to the outside.

The photodiode 512 receives a portion of the light irradiated from the light source 514 and monitors the light irradiated from the light source 514 . The photodiode 512 is disposed on the submount 513 positioned on the stem 510 to receive a portion of the light to be irradiated. The photodiode 512 senses the received light to monitor the light to be irradiated.

The light source 514 irradiates linearly polarized light of a preset wavelength band.

The light source 514 irradiates light polarized in one direction. Here, the light irradiated from the light source 514 has a polarization direction through which the anti-reflection unit 230 to be described later passes. As the irradiated light has a polarization direction in the corresponding direction, it may pass through the anti-reflection unit 530 . Here, light has P polarization and S polarization, and the P polarization component is generally the polarization direction of the light. That is, the light irradiated from the light source 514 is irradiated so that the P-polarization direction passes through the anti-reflection unit 530 .

The light source 514 irradiates light of a preset wavelength band. Here, the light of the preset wavelength band is a wavelength band through which the filter 534 passes. The light source 514 irradiates light of a preset wavelength band so that the light passes through the filter 534 and is irradiated to the outside of the receptacle 130 .

Here, the light source 514 may be implemented as a laser diode (LD), but is not limited thereto.

The lens 516 is disposed in front (-x-axis direction) on the path on which the light is irradiated from the light source 514 to focus the light irradiated from the light source 514 . The lens 516 focuses the light irradiated from the light source 514 so that most of the irradiated light is not dispersed and is incident to the anti-reflection unit 530 to be described later.

The housing 518 is disposed outside the optical transmitter 110 , and protects the internal configuration of the optical transmitter 110 from external forces, and prevents the internal configuration of the optical transmitter 110 from escaping to the outside.

Referring to FIG. 5 , the optical receiver 120 includes an optical filter 520 , a lens 522 , a photodiode 524 , and a stem 526 .

The optical filter 520 is disposed at the frontmost end on the optical path incident to the optical receiver 120 to filter clutter other than the light emitted from other optical transceiving modules.

The lens 520 is disposed behind (on the optical path) (+y-axis direction) of the optical filter 520 to focus the light passing through the optical filter 520 to the photodiode 524 .

The photodiode 524 receives light that is output from another optical transceiver module and flows into the optical transceiver module 100 . The photodiode 524 receives and senses the light output from the other optical transceiving module, thereby receiving a signal transmitted by the other optical transceiving module.

The stem 526 supports the internal components of the optical receiver 120 , particularly the photodiode 524 , and radiates heat generated in the photodiode 524 to the outside.

The anti-reflection unit 530 is disposed in front (-x-axis direction) of the optical transmitter 110 on the optical path, and passes the light irradiated from the optical transmitter 110 but is reflected by the filter 534 or the filter 534 The light passing through and entering the optical transmitter 110 is blocked. The anti-reflection unit 530 has the structure shown in FIG. 6 .

6 is a view showing an anti-reflection unit according to an embodiment of the present invention.

Referring to FIG. 6 , the anti-reflection unit 530 according to an embodiment of the present invention includes a polarizing plate 610 and a quarter wave plate 620 .

The polarizing plate 610 transmits only light in the same direction as the polarization direction of the light output from the optical transmitter 110 .

The quarter wave plate 620 converts the polarization direction of the incident light by 45°.

The light incident from the optical transmitter 110 passes through the polarizing plate 610 and the quarter-wave plate 620 and proceeds with the polarization direction changed. On the other hand, when the light output from the quarter-wave plate 620 is reflected by the filter 534 and the like and is incident on the quarter-wave plate 620 again, the corresponding light passes through the quarter-wave plate 620 and is returned again. The polarization direction is changed by 45°. The light whose polarization direction is converted does not pass through the polarizing plate 610 .

That is, the anti-reflection unit 530 includes a polarizing plate 610 and a quarter-wave plate 620 , and passes light incident from the optical transmitter 110 , but is reflected and travels to the optical transmitter 110 . can be blocked. Since the anti-reflection unit 530 is implemented only with the polarizing plate 610 and the quarter-wave plate 620 , it can operate while occupying a relatively small space and can be implemented at a fairly low cost.

Referring back to FIG. 5 , the filter 534 is disposed in front of the anti-reflection unit 530 on the light path, so that light passing through the anti-reflection unit 530 passes but the light entering through the receptacle 130 is reflect The filter 534 passes light of a preset wavelength band, but reflects light other than the preset wavelength band (adjacent wavelength band). According to this characteristic, since the (transmission) light irradiated from the optical transmitter 110 has a preset wavelength band, it passes through the filter 534 and proceeds to the receptacle 130 . Conversely, the light introduced from the outside into the receptacle 130 has a wavelength band adjacent to a preset wavelength band so that interference with the light output from the optical transceiver module 100 does not occur. According to this characteristic, the (received) light that flows into the filter 534 through the receptacle 130 from the outside is reflected from the filter 534 to the optical receiver 120 .

A light reflection unit 536 is disposed vertically below the filter 534 (the direction opposite to the direction in which light is reflected from the filter, -y-axis direction). The light reflection unit 536 is a structure formed in a housing in which the antireflection unit 530 and the filter 534 are disposed, and changes the direction of light incident thereon. The light reflection unit 536 may have a structure that is concave vertically below the filter 534 or a structure that protrudes convexly. Theoretically, the light output from the optical transmitter 110 and incident on the filter 534 should completely pass through the filter 534, but in reality, the light output from the optical transmitter 110 has a very small ratio to the filter 534. reflection occurs from If the light reflection unit 536 does not exist, the light reflected from the filter 534 is reflected by the housing and flows into the light receiver 120 . When the light reflected from the filter 534 flows into the optical receiver 120, distortion of the result occurs. To prevent this, the light reflection unit 536 (unintentionally) changes the path of the reflected light from the vertically downward direction of the filter 534 to the vertical downward direction. The light whose path is changed by the light reflection unit 536 does not enter the optical receiver 120 .

The receptacle 130 includes a stub 540 and a housing 542 .

The stub 540 is disposed in the housing 542 to output the light output from the optical transmitter 110 to the outside, and transmits the light introduced from the outside to the filter 534 .

The housing 542 includes a stub 540 therein, and protects the stub 540 from external force and fixes the stub 540 .

Referring to FIG. 7 , the heater unit 140 may be implemented as a flexible printed circuit board, and is connected to the rear of the optical transmitter. The heater unit 140 improves the activity of the optical transmitter at a low temperature and reduces the cost.

As shown in FIG. 7A , the heater unit 140 includes a micro heater 710 therein, thereby compensating for the low temperature temperature of the optical transmitter. Alternatively, as shown in FIG. 7B , the heater unit 140 may include a patterned thin film resistor 720 and a micro strip line therein to provide heat. However, the present invention is not necessarily limited thereto, and the heater unit 140 may include a coil therein.

The above description is merely illustrative of the technical idea of this embodiment, and a person skilled in the art to which this embodiment belongs may make various modifications and variations without departing from the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain rather than limit the technical spirit of the present embodiment, and the scope of the technical spirit of the present embodiment is not limited by these embodiments. The protection scope of this embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present embodiment.

CROSS-REFERENCE TO RELATED APPLICATION

*This patent application is based on Article 119(a) of the United States Patent Act (35 USC § 119 for Patent Application No. 10-2020-0096216 and Patent Application No. 10-2020-0096320 filed in Korea on July 31, 2020) If priority is claimed under (a)), all contents thereof are incorporated into this patent application by reference. In addition, if this patent application claims priority for countries other than the United States for the same reason as above, all contents thereof are incorporated into this patent application by reference.

Claims

a light source for irradiating linearly polarized light;

a polarizing filter that passes only light having a preset polarization direction, passes light of a preset wavelength band but reflects light of the remaining wavelength band;

an anti-reflection unit disposed on the optical path of the light source unit and the polarizing filter to pass only light traveling through the polarizing filter;

a ferrule for outputting the light passing through the polarizing filter to the outside; and

A receiving end that receives light reflected from the polarizing filter having a wavelength band other than a preset wavelength band output from the outside

An optical transceiver module comprising a.
.2. The method of claim 1,

The anti-reflection unit,

An optical transceiver module comprising: a polarizing plate that passes only light in a preset polarization direction; and a quarter-wave plate that converts the polarization direction of incident light by 45°.
3. The method of claim 2,

The polarizing plate is

The optical transceiver module, characterized in that it is disposed in front of the 1/4 wave plate on the light path irradiated from the light source unit.
4. The method of claim 3,

The polarizing plate is

The light transmitting and receiving module, characterized in that the light irradiated from the light source unit passes through, but does not pass the light passing through the 1/4 wave plate.