Patent Publication Number: US-2023141411-A1

Title: Passive Optical Network Dual System Module

Description:
RELATED APPLICATIONS 
     This application is a non-provisional of, claims the benefit and priority of Taiwan (R.O.C) Application No. 110213224, filed Nov. 10, 2021, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to an optical module. More particularly, the invention relates to a passive optical network dual system module which can be applied to both systems. 
     BACKGROUND 
     To face the advent of a highly information-based society, communication infrastructure is needed to transmit various kinds of information, such as voice, text, data, images, etc. Accordingly, the optical communication network was developed to replace the conventional copper cable networks for huge information transmission. As known, in the field of optical communication, the optical fiber is especially suitable for serving as the medium for light transmission over long distances due to its advantages of low loss and wide bandwidth. 
     Based on the above advantages, optical detection technology using optical fiber has also become one of the commonly used communications technologies. In optical communication systems, light is used to transmit data to remote ends through optical fibers in the form of light pulses rather than electrical current. Optical fiber transceivers are an important part of communication systems and can be classified according to fiber mode, transmission rate, transmission distance, wavelength and connector type. In the field of optical fiber cable communication, the optical transmission module (Transceiver) has the role of linking the past and the future. Its main function is to convert optical signals into electrical signals, or convert electrical signals into optical signals. One of the optical transmission module type transceivers is a bidirectional transceiver (BiDi), and the main component of is a bi-directional Optical Sub-Assembly (BOSA). 
     Generally, BOSA is made up of light emitter, wherein said light emitter has like laser diode, has the light receiver of light receiving source, can let the light of one wavelength pass but reflect another at the same time. A wavelength optical filter, and an optical transmitter capable of simultaneously outputting the emitted light and inputting the received light, and the above-mentioned components are all covered by a casing. After passing through the optical transmitter, the Tx data is transmitted to the optical fiber in the optical connector through the wavelength filter, and the Rx data is transmitted to the optical receiver through the filter after passing through the optical fiber. 
     For example, one of an optical transmission sub-module is shown as  FIG.  1   . In  FIG.  1   , the optical transmission sub-module  1  includes an optical transmitter  11  capable of outputting and receiving light at the same time and an optical receiver  12  having a light receiving source. In other words, this structure is only suitable for one system of communication protocols. As the demand for data transmission speed increases, the old network system needs to be upgraded to the new system to load a large amount and fast data transmission, and there is a handover period during the upgrade process, that is, during the upgrade process, it needs to serve users who maintain the old network system and upgrade to the new network system at the same time. When there are two systems for the modem in the office building or the transfer station, it is impossible to use one modem to solve it. Therefore, improving the structure of the optical transmission sub-module to cope with the situation of serving two systems at the same time has become an important issue to be considered in the field of optical fiber cable communication. 
     In view of the above, there are many bottlenecks in the prior art, the present invention overcomes the above problems, and proposes a practical passive optical network dual system module. 
     SUMMARY 
     One purpose of the present invention is to provide a kind of passive optical network dual system module, this module can simultaneously support the use of two communication systems, to solve the problem of needing to rearrange optical fiber transmission line and replace data machine. 
     Another object of the present invention is to provide a kind of passive optical network dual system module, this module can simultaneously install two groups of receiving parts and transmitting parts in the narrow space, to solve the problem that only one group receiver and transmitter can be set in a module. 
     To achieve the above-mentioned purpose, the present invention proposes a passive optical network dual system module, the passive optical network dual system module comprises a light guide unit, an optical path conversion unit and an optical transceiver unit. The light guiding unit is connected to an optical fiber and is suitable for transmitting an optical signal, and the optical signal is not a single wavelength. The light path conversion unit is connected to the light guide unit and is suitable for receiving the light signal and changing the light path of the light signal. The light path conversion unit sequentially includes a first one along the direction toward the light guide unit. a collimating lens, a first filter, a second filter, a second collimating lens, a third filter, and a fourth filter, wherein the first collimating lens is disposed on the light guide unit and the light path conversion unit, the second collimating lens is arranged between the second filter and the third filter, wherein the first collimating lens and the second collimating lens make the light The signal forms parallel light. The optical transceiver unit is suitable for receiving and transmitting the optical signal, and is suitable for two sets of communication protocol systems. The optical transceiver unit includes a first receiving element, a second receiving element, a third transmitting element and a fourth transmitting element pieces. The first receiving element is set corresponding to the first filter. The second receiver is arranged corresponding to the second filter. The third emitting element is set corresponding to the third filter. The fourth emitting element is set corresponding to the fourth filter. The first receiving member and the second receiving member are respectively disposed corresponding to one of the third transmitting member and the fourth transmitting member. 
     In some embodiments, when the optical signal is transmitted to the first filter, the incident angle of the optical signal entering the first filter is 45 degrees. 
     In some embodiments, when the optical signal is transmitted to the second filter, the incident angle of the optical signal entering the second filter is 45 degrees. 
     In some embodiments, when the optical signal is transmitted to the third filter, the incident angle of the optical signal entering the third filter is 20 to 30 degrees. 
     In some embodiments, when the optical signal is transmitted to the fourth filter, the incident angle of the optical signal entering the fourth filter is 15 to 25 degrees. 
     In some embodiments, the receiving wavelength range of the first receiving element is between 1575 nm and 1580 nm. 
     In some embodiments, the receiving wavelength range of the second receiving element is between 1490 nm and 1500 nm. 
     In some embodiments, the emission wavelength range of the third emitting element is between 1300 nm and 1320 nm. 
     In some embodiments, the emission wavelength range of the fourth emitting element is between 1260 nm and 1280 nm. 
     In some embodiments, the difference in the emission wavelength range between the third emitting element and the fourth emitting element is not greater than 60 nm. 
     To achieve the above-mentioned purpose, the present invention proposes another passive optical network dual system module, and the passive optical network dual system includes a light guide unit, an optical path conversion unit and an optical transceiver unit. The light guiding unit is connected to an optical fiber and is suitable for transmitting an optical signal, and the optical signal is not of a single wavelength. The light path conversion unit is connected to the light guide unit and is suitable for receiving the light signal and changing the light path of the light signal. The light path conversion unit sequentially includes a first one along the direction toward the light guide unit. Collimating lens, a first filter, a second filter, a second collimating lens and a fifth filter, wherein the first collimating lens and the second collimating lens make the optical signal parallel Light. The optical transceiver unit is suitable for receiving and transmitting the optical signal, and is suitable for two sets of communication protocol systems. The optical transceiver unit includes a first receiving element, a second receiving element, a third transmitting element and a fourth transmitting element pieces. The first receiver is set corresponding to the first filter. The second receiver is arranged corresponding to the second filter. The third emitting element is set corresponding to the fifth filter. The fourth emitting element is set corresponding to the fifth filter. Wherein, the first receiving element and the second receiving element are respectively disposed corresponding to one of the third transmitting element and the fourth transmitting element. 
     In some embodiments, when the optical signal is transmitted to the first filter, the incident angle of the optical signal entering the first filter is 45 degrees. 
     In some embodiments, when the optical signal is transmitted to the second filter, the incident angle of the optical signal entering the second filter is 45 degrees. 
     In some embodiments, when the optical signal is transmitted to the fifth filter, the incident angle of the optical signal entering the fifth filter is 45 degrees. 
     In some embodiments, the receiving wavelength range of the first receiving element is between 1575 and 1580 nm. 
     In some embodiments, the receiving wavelength range of the second receiving element is between 1480 nm and 1500 nm. 
     In some embodiments, the emission wavelength range of the third emitting element is between 1300 nm and 1320 nm. 
     In some embodiments, the emission wavelength of the fourth emitting element ranges from 1260 nm to 1280 nm. 
     In some embodiments, the difference in the emission wavelength range between the third emitting element and the fourth emitting element is not greater than 60 nm. 
     Accordingly, the present invention provides proposes a passive optical network dual system module, which is used in the optical transceiver unit to carry out the configuration of two receiving parts and two transmitting parts, and can be simultaneously on the same optical path. Supports the use of two sets of communication protocols. In addition, by setting the angle of each filter in the optical path conversion unit, two sets of receivers and transmitters can be installed in a narrow space, which not only does not increase the overall occupied space, but also maintains a good signal transmission effect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Unless specified otherwise, the accompanying drawings illustrate aspects of the innovative subject matter described herein. Referring to the drawings, wherein like reference numerals indicate similar parts throughout the several views, several examples of heatsink fins incorporating aspects of the presently disclosed principles are illustrated by way of example, and not by way of limitation. 
         FIG.  1    depicts an optical transmission sub-module of the prior art. 
         FIG.  2    depicts a passive optical network dual system module according to various embodiments of this invention. 
         FIG.  3    depicts a cross-section of a passive optical network dual system module according to various embodiments of this invention. 
         FIG.  4    depicts a cross-section including an optical path of a passive optical network dual system module according to various embodiments of this invention. 
         FIG.  5    depicts a cross-section of the passive optical network dual system module according to various embodiments of this invention. 
         FIG.  6    depicts a cross-section including an optical path of the passive optical network dual system module according to various embodiments of this invention. 
     
    
    
     DETAILED DESCRIPTION 
     To solve the problems in prior art, an optical inspection device is disclosed in the present invention. The optical inspection device of the present invention can detect and/or inspect different positions of an object at the same time without significant changes of the structure and/or element of the interferometer, and can obtain the coherence effect optical information of different optical path. Thus, the optical information can be processed and analyzed. Also, the present invention can be applied to various field of inspection and/or detection, particularly in biological detection/inspection, industrial detection/inspection, semiconductor industrial detection/inspection and so on. 
     Unless specified otherwise, the accompanying drawings illustrate aspects of the innovative subject matter described herein. Referring to the drawings, wherein like reference numerals indicate similar parts throughout the several views, several examples of coaxial cable connector incorporating aspects of the presently disclosed principles are illustrated by way of example, and not by way of limitation. 
     The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
     The embodiment disclosed in this case is a passive optical network dual system module. For example, the passive optical network dual system module can be installed in the optical network unit (ONU) at the customer end of the passive optical network (PON) system. This system is fiber to the curb (FTTC), fiber to the building (FTTB) or fiber-to-the-home (FTTH) systems, using point-to-multipoint network architecture and FTTC, FTTB, FTTH systems and equipment used in remote user residences. 
     First, the structural appearance and preliminary functions of the passive optical network dual system module in this case will be described. Please refer to  FIG.  2   , which is a schematic structural diagram of the passive optical network dual system module of the present invention. The passive optical network dual system module  2  includes a light guide unit  20 , an optical path conversion unit  22  and an optical transceiver unit. The light guide unit  20  is connected to the optical fiber  9 , and the light guide unit  20  is adapted to output optical signals. The light path conversion unit  22  is connected to the light guide unit  20  and is adapted to receive the light signal and change the light path of the light signal. The optical transceiver unit is suitable for receiving and transmitting optical signals. The optical transceiver unit includes a first receiving element  240 , a second receiving element  242 , a third transmitting element  244  and a fourth transmitting element  246 . The first receiving element  240  and the second receiving element  242  are disposed corresponding to one of the third transmitting element  244  and the fourth transmitting element  246 , respectively. In other words, the receiving element and the transmitting element are arranged in pairs, and the installation positions of the receiving element and the transmitting element in  FIG.  2    are only schematic diagrams in the embodiment, and the actual installation positions are still determined according to the layout requirements. 
     Next, the internal structure of the passive optical network dual system module of the present case is further disclosed through a cross-sectional view. Please refer to  FIG.  3   .  FIG.  3    is a schematic structural diagram of a cross-section of the passive optical network dual system module of the creation. The passive optical network dual system module  2  includes a light guide unit  20 , an optical path conversion unit  22  and an optical transceiver unit. The light path conversion unit  22  is connected to the light guide unit  20  and includes a first collimating lens  221 , a first filter  220 , a second filter  222 , and a second collimator in sequence along the direction toward the light guide unit  20 , lens  223  third filter  224 , fourth filter  226 . The optical transceiver unit includes a first receiving element  240 , a second receiving element  242 , a third transmitting element  244  and a fourth transmitting element  246 . Among them, the first receiving part  240  is set corresponding to the first filter  220 . The second receiving part  242  is set corresponding to the second filter  222 . The third transmitting part  244  is set corresponding to the third filter  224 . The fourth transmitting part  246  is set The setting corresponds to the fourth filter  226 . The first collimating lens  221  and the second collimating lens  223  make the light signal form parallel light. 
     The design positions of the above-mentioned filters, receiving parts and transmitting parts will be further described here. It should be noted that, because the device that can install the module of this case is usually located in a relatively narrow space, how to simplify the arrangement of components and reduce the overall space while achieving a good balance is the main consideration when designing the position of the above-mentioned components. In this case, the primary consideration is whether the transmission path of the optical signal is blocked. Once the optical signal is blocked, the transmission effect will be reduced. Therefore, it is necessary to provide a suitable installation space for the receiver and/or the transmitter. However, the movement of any receiver and/or transmitter will increase the collision between components. In addition, when moving the receiving element and/or the transmitting element, the collimating lens and filter inside the optical path conversion unit also need to be adjusted accordingly. In order to reduce the effect of the light spot affecting the signal transmission, the filter at the transmitting end is usually Installed near the light focusing point of the emitting element, the small spot filter can be used in a small size to save space. Therefore, under the consideration of layers, the design of components in the light adjustment unit is a big challenge. 
     Under the above considerations, the detailed path of the light in the optical path conversion unit will be further described here. Please continue to refer to  FIG.  3   , and please refer to  FIG.  4    at the same time. A schematic structural diagram of a cross-section of the system module including the optical path. Since the filtering wavelength of each filter is determined by the requirements of the receiving element and/or the transmitting element corresponding to the filter, only the angle of each filter is described in this case. The way of defining the filter angle is determined by the angle at which the light is incident on the filter. That is, in the passive optical network dual system module  2  described in this case, when the optical signal S (dotted line) is transmitted to the first filter  220 , the incident angle of the optical signal S entering the first filter  220  is 45 degrees. When the optical signal S is transmitted to the second filter  222 , the incident angle of the optical signal S entering the second filter  222  is 45 degrees; when the optical signal S is transmitted to the third filter  224 , the optical signal S enters the third filter  224  The incident angle of S is 20 to 30 degrees, and in this embodiment, it is 25 degrees. When the optical signal is transmitted to the fourth filter  226 , the incident angle of the optical signal S entering the fourth filter  226  is 15 to 25 degrees. In this embodiment, 20 degrees is exemplified. 
     The passive optical network dual system module of the present invention provides another embodiment, please refer to  FIG.  5   , and please refer to  FIG.  6    at the same time.  FIG.  5    is a schematic structural diagram of a cross-section of the passive optical network dual system module created.  FIG.  6    is a schematic structural diagram of a cross-section including an optical path of the passive optical network dual system module created. Since the filtering wavelength of each filter is determined by the requirements of the receiving element and/or the transmitting element corresponding to the filter, only the angle of each filter is described in this case. The way of defining the filter angle is determined by the angle at which the light is incident on the filter. That is, in the passive optical network dual system module  2  described in this case, when the optical signal S (dotted line) is transmitted to the first filter  220 , the incident angle of the optical signal S entering the first filter  220  is 45 degrees. When the optical signal S is transmitted to the second filter  222 , the incident angle of the optical signal S entering the second filter  222  is 45 degrees. When the optical signal S is transmitted to the third filter  224 , the optical signal S enters the third filter  224  The incident angle of S is 20 to 30 degrees, and in this embodiment, it is 25 degrees. When the optical signal is transmitted to the fourth filter  226 , the incident angle of the optical signal S entering the fourth filter  226  is 15 to 25 degrees. In this embodiment, 20 degrees is exemplified. 
     It should be noted that the optical signal in this case is not a single wavelength, and in the case of different wavelengths, if the optical signal is directly transmitted to the light guide unit, the optical signal may be disturbed and resulting in poor reception. Therefore, a first collimating lens and a second collimating lens are arranged in the passive optical network dual system module of the present case, and the two collimating lenses can make the optical signal form parallel light, which is convenient for the receiving element to receive. 
     In the passive optical network dual system module of the present invention, the first receiving element receives wavelengths ranging from 1575 nm to 1580 nm. The second receiving element has a receiving wavelength range from 1480 nm to 1500 nm. The third emission element has an emission wavelength range of 1300 nm to 1320 nm. The fourth emission element has an emission wavelength range of 1260 nm to 1280 nm. And the difference in emission wavelength range between the third emitting element and the fourth emitting element is not greater than 60 nm. 
     Using the passive optical network dual system module described in the present invention, the services of two communication protocol systems can be provided simultaneously in the same structure. For example, GPON (Gigabit-Capable Passive Optical network) can be served simultaneously with XGS-PON (10 Gigabit-Capable Symmetric Passive Optical network). Of course, the above communication system is only an example, and any communication system that can be applied to the passive optical network dual system module in this case should not go beyond the scope of the present invention. 
     Accordingly, the present invention discloses a passive optical network dual system module, and has the following advantages. 
     1. Combining dual-system components in the same module makes it unnecessary to disassemble additional hardware devices such as modems when replacing or using two communication systems at the same time, greatly reducing the cost of replacing the system. 
     2. Through the setting of the collimating lens, the optical signal can form parallel light, which improves the quality of the optical signal received by the receiver. 
     3. Through the design between the third filter and the fourth filter, the setting of the small angle not only greatly saves the overall space, but also reduces the problem of unstable optical signal caused by the light spot. 
     4. By the design of the fifth filter, instead of requiring two filters to correspond to the receiver, not only the overall structure is simpler, but also the overall space is greatly saved, reducing the It solves the problem that the light spot causes the optical signal to be unstable. 
     The presently disclosed inventive concepts are not intended to be limited to the embodiments shown herein, but are to be accorded their full scope consistent with the principles underlying the disclosed concepts herein. Directions and references to an element, such as “up,” “down,”, “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like, do not imply absolute relationships, positions, and/or orientations. Terms of an element, such as “first” and “second” are not literal, but, distinguishing terms. As used herein, terms “comprises” or “comprising” encompass the notions of “including” and “having” and specify the presence of elements, operations, and/or groups or combinations thereof and do not imply preclusion of the presence or addition of one or more other elements, operations and/or groups or combinations thereof. Sequence of operations do not imply absoluteness unless specifically so stated. Reference to an element in the singular, such as by use of the article “a” or “an”, is not intended to mean “one and only one” unless specifically so stated, but rather “one or more”. As used herein, “and/or” means “and” or “or”, as well as “and” and “or.” As used herein, ranges and subranges mean all ranges including whole and/or fractional values therein and language which defines or modifies ranges and subranges, such as “at least,” “greater than,” “less than,” “no more than,” and the like, mean subranges and/or an upper or lower limit. All structural and functional equivalents to the elements of the various embodiments described throughout the disclosure that are known or later come to be known to those of ordinary skill in the relevant art are intended to be encompassed by the features described and claimed herein. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure may ultimately explicitly be recited in the claims. No element or concept disclosed herein or hereafter presented shall be construed under the provisions of 35 USC 112(f) unless the element or concept is expressly recited using the phrase “means for” or “step for”. 
     In view of the many possible embodiments to which the disclosed principles can be applied, we reserve the right to claim any and all combinations of features and acts described herein, including the right to claim all that comes within the scope and spirit of the foregoing description, as well as the combinations recited, literally and equivalently, in the following claims and any claims presented anytime throughout prosecution of this application or any application claiming benefit of or priority from this application.