A small form-factor pluggable double-density multiple passive optical network module

Abstract

The present invention relates to a Small Form-Factor Pluggable Double Density Multiple Passive Optical Network Module (10), projected to provide a connection for 50-GPON, XGS-PON, and GPON, and to be incorporated in any state-of-the-art SFP-DD transceiver host to allow multi-PON OLT technologies. The module (10) comprises a case (113) housing a specific set of technical elements such as a Hexa- bidirectional optical subassembly or Hexa-pho tonic integrated circuit (210), a high-speed electrical interface (112), a control unit (111), a printed circuit board (115) and a flex-printed circuit board or rigid or flex interposer er connectivity circuit (211) to ensure proper assembly and electronic performance of all elements.

Description

[0001] DESCRIPTION

[0002] A SMALL FORM-FACTOR PLUGGABLE DOUBLE -DENSITY MULTIPLE PASSIVE OPTICAL NETWORK MODULE

[0003] FIELD OF THE INVENTION

[0004] The present invention is enclosed in the area of Gigabit passive optical network (GPON) , 10 Gigabit-capable symmetric passive optical network (XGS-PON) , and 50 Gigabit symmetric and asymmetric passive optical network (50G-PON) optical line terminals (OLT) , particularly in the field of small form-factor pluggable modules double density (SFP-DD) .

[0005] PRIOR ART

[0006] Gigabit-capable Passive Optical Network (GPON) has been widely spread among operators allowing the distribution of high bandwidth, and large coverage, and providing high efficiency to deliver broadband. Based on International Telecommunication Union - Telecommunication Standardization Sector (ITU-T) G.984.x. GPON-OLTs commonly use small formfactor pluggable (SFP) transceiver hosts equipped with SFPs in a single fiber bidirectional SC connector configuration for carrying out the transmission and reception of the passive optical network (PON) data.

[0007] 10 Gigabit-capable symmetric Passive Optical Network (XGS-PON) is spreading among operators allowing the distribution of very high bandwidth, large coverage, and providing high efficiency to deliver broadband. It is a PON technology capable of coexisting in the same physical network with legacy GPON ITU-T G. 984.x - by using different downstream and upstream wavelengths. XGS-PON is based on ITU-T G.907.x. XGS-PON Optical Line Terminals (OLTs) commonly use SFP plus transceiver hosts equipped with 10 Gigabit SFP plus in a single fiber bidirectional SC connector configuration for carrying out the transmission and reception of the 10 Gigabit passive optical network ( PON) data .

[0008] 50 Gigabit Symmetric and asymmetric Passive Optical Network ( 50G-PON) is a new PON technology delivering 50 Gigabit per second symmetric or asymmetric bandwidth . It is a PON technology capable of coexisting in the same physical network with legacy GPON based on ITU-T G . 984 . x and XGS-PON based on ITU-T G . 907 . x by using di f ferent downstream and upstream wavelengths . The 50G-PON is based on ITU-T G . 9804 .

[0009] SFPs comprise a metallic case , a printed circuit board ( PCB ) , a Bi-Directional Optical Sub-Assembly (BOSA) , and flexible PCBs to connect the BOSA to the PCB . BOSA presently comprises a metal housing with a Transmitter Optical Sub-Assembly ( TOSA) for optical transmitting, a Receiver Optical Sub-Assembly (ROSA) for optical receiving, an optical fiber or an optical connector to connect an optical fiber that connects to the external network and a device used to route the light to and from the optical fiber .

[0010] PROBLEM TO BE SOLVED

[0011] Current PON optical transceiver modules for GPON, XGS-PON, or 50G-PON support j ust one of the prior PON technologies , this is , by employing a bidirectional SC connector, a single SFP, SFP+ , SFP56 or QSFP28 is adapted to feed a GPON, an XGS-PON or a 50G-PON, limiting the number of users connected to the said host and thereby limiting also its density . The coexistence of the several PON technologies is only possible using external passive coexistence elements and more than one OLT port .

[0012] The present invention addresses the above problem . SUMMARY OF THE INVENTION

[0013] The present invention relates to a Small Formfactor Pluggable Double-Density Multiple Passive Optical Network Module ( SFPDD-MPM) , proj ected to provide a connection to one optical fiber connector of a PON, and to be incorporated in any state-of-the-art OLT supporting GPON, XGS-PON, and 50G-PON .

[0014] Due to the set of technical features that characteri zes the SFPDD-MPM optical module developed, it is possible to triple the density of a transceiver, that is , for the same cage space , it allows the coexistence of the three PON technologies . The SFPDD-MPM allows the transmitting and receiving of 3 PON channels in a single optical transceiver .

[0015] DESCRIPTION OF FIGURES

[0016] Figure 1 is a schematic diagram of the SFPDD-MPM optical module developed based on a hexa bidirectional optical subassembly, according to certain aspects of the invention . The numerical references represent :

[0017] 10 - SFPDD-MPM optical module ;

[0018] 110 - hexa bidirectional optical subassembly;

[0019] 111 - control unit ;

[0020] 112 - high-speed electrical interface ;

[0021] 113 - case ;

[0022] 114 - flex-printed circuit board;

[0023] 115 - printed circuit board .

[0024] Figure 2 is a schematic diagram of the SFPDD-MPM optical module developed based on a Hexa-photonic integrated circuit (PIC) , according to certain aspects of the invention. The numerical references represent:

[0025] 10 - SFPDD-MPM optical module;

[0026] 111 - control unit;

[0027] 112 - high-speed electrical interface;

[0028] 113 - case;

[0029] 115 - printed circuit board;

[0030] 210 - hexa-photonic integrated circuit;

[0031] 211 - rigid or flex interposer or connectivity circuit (can be among others, wire bond, flip chip bumps or balls, interposer circuit board, flex-printed circuit board)

[0032] 212 - fiber;

[0033] 213 - ferrule.

[0034] Figure 3 is a schematic diagram of the SFPDD-MPM module's control unit, according to certain aspects of the invention. The numerical references represent:

[0035] 111 - control unit;

[0036] 112 - high-speed electrical interface;

[0037] 310 - modulation sub-unit;

[0038] 311 - microcontroller;

[0039] 312 - power supply.

[0040] Figure 4 is a diagram of the SFPDD-MPM module contact assignment of the 40 pins high-speed electrical interface (HSEI) to the SFPDD transceiver host to support the GPON, XGS-PON, and 50G-PON. It can assume five options depending on the lane interface modulation and PON bitrate symmetry, this is, lane interface based on 4-level Pulse Amplitude Modulation (PAM4) or lane interface based on 2-level Amplitude Modulation (NRZ) according to certain aspects of the invention. Option 1 - two times 25G NRZ downstream, two times 25G NRZ upstream. Option 2 - 25GBd PAM4 downstream,

[0041] RECTIFIED SHEET (RULE 91) ISA / EP 25GBd PAM4 and / or 25G NRZ and / or 12 . 5G NRZ upstream . Option 3 - 50G NRZ downstream, 50G NRZ and / or 25G NRZ or 12 . 5 NRZ upstream . Option 4 - two times 25G NRZ downstream, 25G NRZ and / or 12 . 5G NRZ upstream . Option 5 - 50G NRZ downstream, 25G NRZ and / or 12 . 5G NRZ upstream .

[0042] The module contact assignment is defined as :

[0043] • Pin number 1 - GPON_TD+ - Transmit Non- Inverted GPON Data Input ;

[0044] • Pin number 2 - GPON_TD- - Transmit Inverted GPON Data Input ;

[0045] • Pin number 3 - GND - Module ground;

[0046] • Pin number 4 - SDA - 2-Wire Serial Interface Data Line ;

[0047] • Pin number 5 - SCL - 2-Wire Serial Interface Clock;

[0048] • Pin number 6 - GPON_RD- - Receive Burst Mode Inverted

[0049] GPON Data output ;

[0050] • Pin number 7 - Reset / Rateselect -Reset Receiver Burst Mode XGS-PON, Rate select for XGS-PON or XG-PON upstream bursts ;

[0051] • Pin number 8 - XGSPON_SD - Receiver Signal Detect indicator for XGS-PON receiver ;

[0052] • Pin number 9 - Trig_TxDisable - Two signals multiplex, which is selected by register : Receiver signal strength indication trigger and transmitter disable for GPON and XGS-PON;

[0053] • Pin number 10 - GPON_RD+ - Receive Burst Mode Noninverted GPON Data output ;

[0054] • Pin number 11 - GND - module ground;

[0055] • Pin number 12 - XGSPON_RD- - Receive Burst Mode Inverted XGSPON Data output ;

[0056] • Pin number 13 - XGSPON_RD+ - Receive Burst Mode Noninverted XGS-PON Data output ;

[0057] • Pin number 14 - GPON_SD - Receiver Signal Detect indicator for GPON receiver ; • Pin number 15 - VccR - power supply for the receiver;

[0058] • Pin number 16 - VccT - power supply for the transmitter;

[0059] • Pin number 17 - GPON_Reset - Reset Receiver Burst Mode GPON;

[0060] • Pin number 18 - XGSPON_TD+ - Transmit Non-Inverted XGS- PON Data Input;

[0061] • Pin number 19 - XGSPON_TD- - Transmit Inverted XGS-PON Data Input;

[0062] • Pin number 20 - GND - Module ground;

[0063] • Pin number 21 - o Option 1 and 4: 50GPON_TD2+ - Second 25G NRZ Transmit Non-Inverted 50G-PON Data Input; o Option 2, 3 and 5: GND - Module ground;

[0064] • Pin number 22 - o Option 1 and 4: 50GPON_TD2- - Second 25G NRZ Transmit Inverted 50G-PON Data Input; o Option 2,3 and 5: TX_Fault - 50G-PON Transmitter fault output indication;

[0065] • Pin number 23 - TX_Disable - 50G-PON Transmitter disable ;

[0066] • Pin number 24 - NG - Not connected;

[0067] • Pin number 25 - NG - Not connected;

[0068] • Pin number 26 - o Option 1: 50GPON_RD2- - Second 25G NRZ Receive Burst Mode Inverted 50G-PON Data output; o Option 2,3,4 and 5: GND - Module ground;

[0069] • Pin number 27 - Reset / Rateselect -Reset Receiver Burst Mode 50G-PON, Rate select for 12.5&25G or 50G upstream bursts ;

[0070] • Pin number 28 - 50GPON_RXSD - Receiver Signal Detect indicator for the 50G-PON receiver; • Pin number 29 - Trig - Receiver signal strength indication trigger for 50G-PON;

[0071] • Pin number 30 - o Option 1: 50GPON_RD2+ - Second 25G NRZ Receive Burst Mode 50G-PON Data output; o Option 2,3,4 and 5: GND - Module ground;

[0072] • Pin number 31 - GND - Module ground;

[0073] • Pin number 32 - o Option 1: 50GPON_RD1- - First 25G NRZ, 12.5G NRZ Receive Burst Mode Inverted 50G-PON Data output; o Option 2: 50GPON_RD- - 25GBd PAM4, 25G NRZ and 12.5G NRZ Receive Burst Mode Inverted 50G-PON Data output ; o Option 3: 50GPON_RD- - 50G NRZ, 25G NRZ and 12.5G NRZ Receive Burst Mode Inverted 50G-PON Data output ; o Option 4 and 5: 50GPON_RD- - 25G NRZ and 12.5G NRZ Receive Burst Mode Inverted 50G-PON Data output;

[0074] • Pin number 33 - o Option 1: 50GPON_RD+ - First 25G NRZ. 12.5G NRZ Receive Burst Mode Non-Inverted 50G-PON Data output ; o Option 2: 50GPON_RD+ - 25GBd PAM4, 25G NRZ and 12.5G NRZ Receive Burst Mode Non-Inverted 50G-PON Data output; o Option 3: 50GPON_RD+ - 50G NRZ, 25G NRZ and 12.5G NRZ Receive Burst Mode Non-Inverted 50G-PON Data output ; o Option 4 and 5: 50GPON_RD+ - 25G NRZ and 12.5G NRZ Receive Burst Mode Non-Inverted 50G-PON Data output ;

[0075] • Pin number 34 - GND - Module ground;

[0076] • Pin number 35 - VccR - power supply for the receiver; • Pin number 36 - VccT - power supply for the transmitter;

[0077] • Pin number 37 - GND - Module ground;

[0078] • Pin number 38 - o Option 1 and 4: 50GPON_TD1+ - First 25G NRZ Transmit Non-Inverted 50G-PON Data Input; o Option 2: 50GPON_TD+ - 25GBd PAM4 Transmit Noninverted 50G-PON Data Input; o Option 3 and 5: 50GPON_TD+ - 50G NRZ Transmit Noninverted 50G-PON Data Input;

[0079] • Pin number 39 - o Option 1 and 4: 50GPON_TD1- - First 25G NRZ Transmit Inverted 50G-PON Data Input; o Option 2: 50GPON_TD- - 25GBd PAM4 Transmit Inverted 50G-PON Data Input; o Option 3 and 5: 50GPON_TD- - 50G NRZ Transmit Inverted 50G-PON Data Input;

[0080] • Pin number 40 - GND - module ground

[0081] Figure 5 is a schematic diagram of a Hexa bidirectional optical subassembly (BOSA) (110) package for use in the transceiver module shown in Figure 1. The Hexa-BOSA (110) package comprises a housing with an optical coupling receptacle (401) on one end and the other end along the same axis there is a transmitter optical subassembly (TOSA) (407) . Between the optical coupling receptacle (401) and the TOSA (407) , and on a perpendicular axis, there are two more TOSAs and three receiver optical subassemblies (ROSAs) , which can be positioned both above and / or below the axis, but with the optical interface turned to the interior of the housing. A first ROSA (402) is positioned below the mentioned axis, being the closest to the optical coupling receptacle (401) . The second closest subassembly is a second ROSA (403) , positioned above the axis. The third closest subassembly is a third ROSA (404) , positioned below the axis. Keeping in the same direction there is a first TOSA (405) , positioned above the axis, and then a second TOSA (406) , positioned below the axis.

[0082] Figure 6 illustrates the optical routing scheme (500) that may be employed in a Hexa-BOSA such as module (110) . The optical routing scheme may be attained using several wavelength division multiplexer (WDM) filters which may be coated such that one wavelength, different in each filter, may be reflected and the rest of the spectrum pass through it. These filters are represented by numbers (408) , (409) , (410) , (411) , and (412) . The wavelength reflected in each filter shall be the same as the one used on the TOSA or ROSA aligned with the respective WDM filter. In this way, a wavelength from a TOSA is reflected on the filter and routed to the optical fiber or optical coupling receptacle. In the same way, a signal received from the optical fiber or the optical coupling receptacle shall pass the filter, except for one wavelength that should be reflected by the filter to be received on the ROSA.

[0083] Figure 7a) to 7f) are options for the schematic diagram of a Hexa bidirectional optical subassembly PIC based (PIC- BOSA) (110) package for use in the transceiver module shown in Figure! .

[0084] The numerical references represent:

[0085] 210 - PIC-Hexa-BOSA;

[0086] 600- holder;

[0087] 601 - optical coupling receptacle;

[0088] 602 - fiber;

[0089] 603 - V-groove;

[0090] 700 - WDM passive filter with several stages of adddrop filters; 701 - 50G-PON upstream add-drop filter;

[0091] 702 - XGS-PON upstream add-drop filter;

[0092] 703 - GPON upstream add-drop filter;

[0093] 704 - GPON dowstream add-drop filter;

[0094] 705 - XGS-PON dowsntream add-drop filter;

[0095] 706 - 50G-PON dowsntream add-drop filter;

[0096] 710 - optical modulator;

[0097] 711 - optical modulator;

[0098] 800 - lenses or photonic wire bonds;

[0099] 801 - lenses or photonic wire bonds;

[0100] 802 - lenses or photonic wire bonds;

[0101] 803 - lenses or photonic wire bonds;

[0102] 804 - lenses or photonic wire bonds;

[0103] 805 - lenses or photonic wire bonds;

[0104] 810 - interposer, wire bond or simple deposited electrical waveguides and pads;

[0105] 811 - interposer, wire bond or simple deposited electrical waveguides and pads;

[0106] 812 - interposer, wire bond or simple deposited electrical waveguides and pads;

[0107] 900- PIN or APD;

[0108] 901- PIN or APD;

[0109] 902 - PIN or APD;

[0110] 903 - light source;

[0111] 904 - light source;

[0112] 905 - light source;

[0113] 910 - PIN or APD;

[0114] 911 - PIN or APD;

[0115] 912 - PIN or APD;

[0116] 913 - built in monolithically laser source;

[0117] 914 - built in monolithically laser source;

[0118] 915 - built in monolithically laser source; Figure 8 is a view of the case of the SFPDD-MPM ' s optical module developed with a single SC connector for integrating the Hexa-bosa and / or the hexa-Photonic Integrated Circuit , according to certain aspects of the invention . The numerical references represent :

[0119] 610 - MSA height of the rear part ;

[0120] 620 - MSA width of the rear part ;

[0121] 630 - MSA length of the transceiver, rear part ;

[0122] 640 - front length;

[0123] 650 - front width;

[0124] 660 - front height ;

[0125] 670 - total length of the transceiver .

[0126] Figure 9 is an exploded view of the case and internal components of the SFPDD-MPM optical module developed with a SC connector, according to certain aspects of the invention . The numerical references represent :

[0127] 110 - Hexa-bidirectional optical sub-assembly;

[0128] 114 - printed circuit board;

[0129] 770 - bottom case ;

[0130] 720 - top case ;

[0131] 730 - actuator tines ;

[0132] 740 - pull-tab ;

[0133] 750 - SC hexa-bidirectional optical sub-assembly support ;

[0134] 760 - case spacer .

[0135] Figure 10 is an exploded view of the case and internal components of the SFPDD-MPM optical module developed with a SC connector, according to certain aspects of the invention . The numerical references represent :

[0136] 210 - hexa-photonic integrated circuit ; 211 - rigid or flex interposer or connectivity circuit (can be among others, wire bond, flip chip bumps or balls, interposer circuit board, flex-printed circuit board) ;

[0137] 212 - fiber;

[0138] 213 - SC ferrule;

[0139] 114 - printed circuit board;

[0140] 770 - bottom case;

[0141] 720 - top case;

[0142] 730 - actuator tines;

[0143] 740 - pull-tab;

[0144] 750 - SC ferrule support;

[0145] 760 - case spacer.

[0146] DETAILED DESCRIPTION

[0147] The following detailed description has references to the figures. Parts that are common in different figures have been referred to using the same numbers. Also, the following detailed description does not limit the scope of the disclosure.

[0148] The present invention relates to an SFPDD-MPM optical module comprising a single SC connector, projected to be connected in an SFP-DD transceiver host, allowing it to operate in GPON, XGS-PON, and 50G-PON transmitter and receiver simultaneously.

[0149] According to the main embodiment of the invention, the SFPDD-MPM optical module (10) is comprised of at least a hexa-bidirectional optical subassembly (110) - Hexa-BOSA - or a hexa-photonic integrated circuit (210) , a control unit (111) comprising connection and processing means adapted to drive and control said Hexa-BOSA (110) or PIC (210) and a high-speed electrical interface - HSEI - (112) adapted to provide connection to the SFP-DD transceiver host Optical Network Units. These elements comprising the SFPDD- MPM optical module (10) are housed in a case (113) which is to be installed inside the SFP-DD transceiver host cage of a GPON, XGS-PON, and 50G-PON OLT .

[0150] Figure 1 illustrates the block diagram of an exemplary embodiment of the SFPDD-MPM optical module (10) of the invention. It is comprised of the case (113) housing one Hexa-BOSA (110) for GPON, XGS-PON, and 50G-PON connection, the control unit (111) , and the high-speed electrical interface (112) .

[0151] Figure 2 illustrates the block diagram of an exemplary embodiment of the SFPDD-MPM optical module (10) of the invention. It is comprised of the case (113) housing one PIC (210) for GPON, XGS-PON, and 50G-PON connection, the control unit (111) , and the high-speed electrical interface (112) .

[0152] The Hexa-BOSA (110) is composed of a laser working on the 50G-PON downstream wavelength at 49.76 Gbit / s, a three-rate burst mode receiver working on the 50G-PON upstream wavelength at 12.44 Gbit / s, 24.88 Gbit / s and 49.76 Gbit / s, a laser working on XGS-PON downstream wavelength at 9.95 Gbit / s, a dual-rate burst mode receiver working on XGS- PON upstream wavelength at 2.48 Gbit / s and 9.95 Gbit / s, a laser working on GPON downstream wavelength at 2.48 Gbit / s and a burst mode receiver working on GPON upstream wavelength at 1.24 Gbit / s. The Hexa-BOSA (110) further includes an SC ferrule to allow the connection to an SC optical fiber connector .

[0153] The PIC (210) is composed of a laser working on the 50G-PON downstream wavelength at 49.76 Gbit / s, a three- rate burst mode receiver working on the 50G-PON upstream wavelength at 12.44 Gbit / s, 24.88 Gbit / s and 49.76 Gbit / s, a laser working on XGS-PON downstream wavelength at 9.95 Gbit / s, a dual-rate burst mode receiver working on XGS-PON upstream wavelength at 2.48 Gbit / s and 9.95 Gbit / s, a laser working on GPON downstream wavelength at 2.48 Gbit / s and a burst mode receiver working on GPON upstream wavelength at 1.24 Gbit / s. The PIC (210) further includes an optical fiber coupled to an SC ferrule to allow the connection to an optical fiber connector.

[0154] The control unit (111) is shown in Figure 3 and is adapted to control the Hexa-BOSA (110) and / or the PIC (210) . For that purpose, the control unit (111) comprises three modulation sub-units (310) and a microcontroller (311) , besides the required circuit electronics that comprise resistors, capacitors, power supply (312) , and ferrite bead. The modulation sub-units (310) comprise laser drivers and limiting amplifiers adapted to drive and modulate the specific technology lasers and to amplify the electrical signals from the single and dual-rate burst mode receivers of Hexa-BOSA (110) or PIC (210) . The microcontroller (311) is configured to control the modulation sub-units (310) and to communicate with the SFP-DD host through the HSEI (112) . The microcontroller (311) is also configured to control the Hexa-BOSA power supplies (312) . In one embodiment, the Hexa- BOSA (110) is connected to the control unit (111) through six flex printed circuit boards (114) . More particularly, the Hexa-BOSA (110) is connected to the modulation sub-units (310) of the control unit (111) , and in particular to the respective laser driver and limiting amplifier through the flexible printed circuit board (114) , to guarantee the electronic performance. In another embodiment, the control unit (111) is mounted in a printed circuit board (115) containing all the necessary electrical connections between the different elements to control and drive the Hexa-BOSA (110) . In another embodiment, the PIC (210) package is mounted in the printed circuit board (115) containing all the necessary electrical connections between the different elements to control and drive the PIC (210) . More particularly, the PIC (210) is connected to the modulation sub-units (310) of the control unit (111) , and in particular to the respective laser driver and limiting amplifier through the printed circuit board (115) to guarantee the electronic performance .

[0155] The modulation sub-units (310) comprise laser drivers and limiting amplifiers adapted to convert PAM4 or NRZ signals from HSEI (112) to drive and modulate the specific technology lasers and to amplify the electrical signals from the single and three-rate burst mode receivers of Hexa-BOSA (110) or PIC (210) .

[0156] The forty pin HSEI (112) is configured to provide a high-speed interconnection to the SFP-DD transceiver host, to transmit electrical signals that were transformed by the SFPDD-MPM optical module (10) from the different PON data received. Similarly, the SFPDD-MPM optical module (10) may receive electrical signals from the SFP-DD transceiver host via said port connector, to be transformed to optical signals and send to a fiber network via optical connection.

[0157] For the connection with the SFP-DD transceiver host, the HSEI (112) comprises a port connector including a plurality of connection pins. In a particular embodiment, the port connector of the forty pins HSEI (112) is provided with a specific contact assignment, to ensure adaptability and compatibility with the state-of-the-art SFP-DD transceiver hosts. HSEI (112) can assume five options depending on the lane interface modulation and PON bitrate symmetry, this is, lane interface based on 4-level Pulse Amplitude Modulation (PAM4) or lane interface based on 2- level Amplitude Modulation (NRZ) .For 50G-PON HSEI pins number 21 to 40 can assume 5 options: Option 1 - two times 25G NRZ downstream, two times 25G NRZ upstream; Option 2 - 25GBd PAM4 downstream, 25GBd PAM4 and / or 25G NRZ and / or 12.5G NRZ upstream; Option 3 - 50G NRZ downstream, 50G NRZ and / or 25G NRZ or 12.5 NRZ upstream; Option 4 - two times 25G NRZ downstream, 25G NRZ and / or 12.5G NRZ upstream; Option 5 - 50G NRZ downstream, 25G NRZ and / or 12.5G NRZ upstream; allowing both symmetric 50G-PON, this is, 49.76 Gbit / s downstream, 12.44 Gbit / s, 24.88 Gbit / s and 49.76 Gbit / s upstream, and assymmetric 50G-PON, this is 49.76 Gbit / s downstream, 12.44 Gbit / s and 24.88 Gbit / supstream Under a particular embodiment of the HSEI (112) , Figure 4 depicts a port connector and respective receptacle which is comprised of forty pins. In the embodiment illustrated in Figure 4, pin 9 is used to both disable the GPON and XGS-PON lasers transmission and to measure the optical input power on the receivers of the GPON and XGS-PON Hexa-BOSA (110) or PIC (210) , representing the received signal strength indication - RSSI. This pin function is selected on a memory pin map of the SFP-DD module, through the SDA (data line) and SCL (clock line) pins, stored on the memory of the microcontroller (220) , to act as transmitter disable of the GPON and XGS-PON of the Hexa-BOSA (110) or PIC (210) , or as RSSI of the GPON and XGS-PON of the Hexa-BOSA (110) or PIC (210) . In the embodiment illustrated in Figure 4, pin 29 is used to disable the 50G-PON laser transmission and to measure the optical input power on the receiver of the 50G-PON Hexa-BOSA (110) or PIC (210) , representing the remote signal strength indication - RSSI. This pin function is selected on a memory pin map of the SFP-DD module, through the SDA (data line) and SCL (clock line) pins, stored on the memory of the microcontroller (220) , to act as transmitter disable of the 50G-PON a of the Hexa-BOSA (110) or PIC (210) , or as RSSI of the 50G-PON of the Hexa-BOSA (110) or PIC (210) .

[0158] Figure 5 illustrates a possible schematic realization of a Hexa-BOSA. In this representation, there are three transmitters and three receivers, each one for transmitting or receiving at a different wavelength, according to the technology of choice. The Hexa-BOSA may be comprised by three ROSAs (402, 403, 404) , each in a transistor outline (TO) package, three TOSAs (405, 406, 407) , each in a TO package, five WDM filters (408, 409, 410, 411, 412) and five slots to mount the WDM filters, and by an optical coupling receptacle (401) with an optical fiber attached and which is in optical communication with all the TOSAs (405, 406, 407) and ROSAs (402, 403, 404) inside the package. Particularly, all the ROSAs (402, 403, 404) and TOSAs (405, 406, 407) are misaligned between each other, and all the WDM filters (408, 409, 410, 411, 412) are placed at a specific angle concerning the direction of light coming from or going to the optical fiber, and each WDM filter (408, 409, 410, 411, 412) is aligned with the respective ROSA (402, 403, 404) or TOSA (405, 406, 407) , regarding the wavelength that the WDM filter reflects.

[0159] Figure 6 represents the optical routing scheme inside the Hexa-BOSA (110) . The basic element to achieve this optical routing scheme is a group of WDM filters, positioned in front of each TOSA and ROSA. A wavelength from a TOSA is reflected on the filter and routed to the optical fiber or optical coupling receptacle. In the same way, a signal received from the optical fiber or the optical coupling receptacle shall pass the filter, except for one wavelength band that should be reflected by the filter to be received on the ROSA.

[0160] Figure 7a) to 7f) are options for the schematic diagram of a Hexa bidirectional optical subassembly PIC based (PIC-BOSA) (110) package for use in the transceiver module shown in Figure! . The PIC-Hexa-BOSA (210) package comprises a holder (600) which has a V-groove (603) for connecting a fiber (602) which holds an optical coupling receptacle (601) . This holder (600) has also the function of allowing hybrid assembling the different devices, keeping them together and aligned for option a) and b) (700, 900 to 905, 800 to 805, 810 to 815) ; option c) and d) (700, 903 to 905, 803 to 805, 810 to 815) ; option e) (700, 800 to 802, 900 to 902, 810 to 815) ; option e) (700, 810 to 815) . In option a) (700) is a WDM passive filter with several stages of add-drop filters (701 to 706) each shaped to meet the required technology, which in an instantiation, can be from left to right 50G-PON upstream (701) , XGS-PON upstream (702) , GPON upstream (703) , GPON downstream (704) , XGS-PON downstream (705) , 50G-PON downstream (706) which characteristics can be obtained from each of the standards. Option b) is in similar to option a) however it has in the optical paths from (705 and 706) a modulator in each (710) and (711) , which simplifies the light sources (904) and (905) to be a continuous wave (GW) laser. In option c) (700) is a WDM passive filter exactly matching the configuration of the WDM filter of option a) , however in this configuration (701 to 703) are connected through a waveguide to an integrated PIN or APD (910-912) respectively. Option d) , is the same as Option c) , however, as in variant option b) there are two modulators (710) and (711) which allow (904) and (905) to be a simple GW laser. Option e) holds the same WDM as in option a) and the receivers as in options a) and b) however the laser sources are built monolithically inside 700 (913 to 915) . In Option f) (700) holds monolithically the receivers (910 to 912) , the transmitters (913 to 915) and its connections to the exiting WDM filters (701 to 706) similar to option a) . (800 to 805) are lenses or photonic wire bonds which, in the used options, connect to each of the discrete devices, serving as interface for the photonic path. (900 to 902) are external receivers, which can be instantiated as PINs or APDs, which are connected electrically through an interposer, wire bond or simple deposited electrical waveguides and pads, (810 to 812) . (903 to 905) are optical sources which can be intrinsically directly modulated lasers (DML) , externally modulated lasers (EML) or CW, considering each of the specific configurations, which are driven though the electrical connections (interposer, wire bond or simple deposited electrical waveguides and pads) to the external drivers .

[0161] Figure 8 illustrates the mechanical case (113) design of the SFPDD-MPM optical module (10) developed. It assumes a standard SFP-DD Transceiver Multisource Agreement (MSA) size inside a cage assembly: MSA height of the rear part (610) , MSA width of the rear part (620) , and MSA length of transceiver outside of the cage to rear (630) to fit on a standard SFP-DD Cage Assembly of the SFP-DD transceiver host. The SFPDD-MPM optical module (10) dimensions outside of the cage MSA, to fit the Hexa-bosa and an SC connector, assume a specific front length (640) of 49,25 mm, front width (650) of 14 mm, and a front height (660) of 12 mm. The total length of the transceiver (670) is 103,40 mm.

[0162] The SFPDD-MPM optical module comprises a case (113) which includes an SC BOSA / ferrule support (750) and a case spacer (760) adapted to accommodate the installation of the Hexa-BOSA (110) or PIC (210) . Additionally, and as shown in Figure 9 and Figure 10, the case (113) may also comprise other mechanical parts such as a bottom case (770) , a top case (720) , one actuator tine (730) to allow the extraction of the SFPDD-MPM optical module (10) from the SFP-DD transceiver host case, and a pull-tab (740) to allow to manually pull the SFPDD-MPM optical module (10) .

[0163] The SFPDD-MPM optical module mechanical parts, (770) , (720) , (730) , (740) , (760) are made from several types of metallic materials as zinc alloys, zamak 2, zamak 3, or aluminum. The SC BOSA supports (750) are manufactured in plastic or metal. The physical geometry of the SFPDD-MPM optical module (10) developed is to be such that it may fit within the receptacle case of a conventional GPON and XGS-PON OLT transceiver .

[0164] The SFPDD-MPM optical module (10) developed may be one of the multiple SFPDD-MPM optical modules (10) incorporated into SFP-DD transceiver hosts of a GPON, XGS- PON, and 50G-PON OLT. In certain embodiments, inserting an SFPDD-MPM optical module (10) into an SFP-DD transceiver host configured to operate just in GPON, XGS-PON or 50G-PON may result in the SFPDD-MPM optical module (10) being only able to establish a single optical connection.

[0165] As will be clear to one skilled in the art, the present invention should not be limited to the embodiments described herein, and several changes are possible which remain within the scope of the present invention.

[0166] Of course, the preferred embodiments shown above are combinable, in the different possible forms, being herein avoided the repetition of all such combinations.

Claims

CLAIMS1. A small form-factor pluggable double-density multiple passive optical network module (10) - SFPDD-MPM - projected to be incorporated in a small form-factor double density - SFP-DD - transceiver host of a 50G-PON optical network line - OLT -, XGS-PON-OLT and GPON-OLT; the optical module (10) being characterized by comprising:— a case (113) housing:- at least a Hexa-bidirectional optical subassembly(110) - Hexa-BOSA; or at least a Hexa-photonic integrated circuit subassembly (210) - PIC;- a control unit (111) comprising connection and processing means adapted to drive and control the Hexa-BOSA (110) subassembly or the PIC (210) subassembly; and- a high-speed electrical interface (112) - HSEI adapted to provide connection to a SFP-DD transceiver host of a GPON, XGS-PON, and 50G-PON OLT.

2. The module (10) according to claim 1, wherein the Hexa-BOSA (110) subassembly comprises:- three receiver optical subassemblies (402, 403, 404) - ROSA -, each in a transistor outline (TO) package;- three transmitter optical subassemblies (405, 406, 407) - TOSA -, each in a TO package;- five wavelength division multiplexing filters (408, 409, 410, 411, 412) - WDM filter - and five slots to mount the WDM filters; and- an optical coupling receptacle (401) with an optical fiber attached, and which is in optical communicationwith all the TOSAs (405, 406, 407) and ROSAs (402, 403, 404) inside the TO package; wherein, all the ROSAs (402, 403, 404) and TOSAs (405, 406, 407) are misaligned between each other; and wherein all the WDM filters (408, 409, 410, 411, 412) are placed at an angle concerning the direction of light coming from or going to the optical fiber of the receptacle (401) , and each WDM filter (408, 409, 410, 411, 412) is aligned with the respective ROSA (402, 403, 404) or TOSA (405, 406, 407) , regarding the wavelength that the WDM filter reflects.

3. The module (10) according to claim 2, wherein the Hexa-BOSA (110) subassembly further comprises:- a first laser, adapted to operate on the fifty-gigabit passive optical network - 50G-PON - downstream wavelengths at 49.76 Gbit / s;- a second laser adapted to operate on the ten-gigabit passive optical network - XGS-PON - downstream wavelengths at 9.95 Gbit / s; and- a third laser adapted to operate on the two-point- five gigabit passive optical network - GPON -, downstream wavelengths at 2.48 Gbit / s.

4. The module (10) according to claim 3, wherein the Hexa-BOSA (110) subassembly comprises:- a first three-rate burst mode receiver adapted to operate on the 50G-PON upstream wavelength at 12.44 Gbit / s, 24.88 Gbit / s and 49.76 Gbit / s;- a second dual-rate burst mode receiver adapted to operate on the XGS-PON upstream wavelength at 2.48 Gbit / s and 9.95 Gbit / s; and- a burst mode receiver adapted to operate on the GPON upstream wavelength at 1.24 Gbit / s.

5. The module (10) according to any of the previous claims, wherein the PIC (210) subassembly comprises:- a holder (600) which has a V-groove (603) for connecting a fiber (602) which holds an optical coupling receptacle (601) ; the holder being configured to allow hybrid assembling different devices keeping them together and aligned;- a WDM passive filter (700) , design in a photonic integrated circuit to meet the requirements of coexistence 50G-PON, XGS-PON and GPON;- optical paths (705 and 706) for optical modulators (710) , (711) ;- a waveguide to integrated PIN or APD (910-912) ;- laser sources built in monolithically (913-915) ;- receivers built in monolithically (910-912) ;- lenses or photonic wire bonds (800-805) which connect to each of the discrete devices, serving as interface for the photonic integrated circuit;- optical sources (903-905) which can be intrinsically directly modulated lasers, externally modulated lasers or continuous wave; andElectrical connections.

6. The module (10) according to any of the previous claims, wherein the Hexa-BOSA (110) and PIC (210) assemblies further comprise an SC ferrule adapted to provide connection to an SC optical fiber connector.

7. The module (10) according to any of the previous claims, wherein the control unit (111) comprises: a modulation sub-unit (310) comprising three laser drivers and three limiting amplifiers elements, adapted to drive and modulate the lasers and to amplify the electrical signals from the single, dual-rate and tri-rate burst mode receiver of the Hexa-BOSA (110) or PIC (210) ; and a microcontroller (311) configured to communicate with the SFP-DD transceiver host through the HSEI (112) and to control the operation of the modulation sub-unit (310) .

8. The module (10) according to claim 7, wherein the connection between the Hexa-BOSA (110) and the respective laser driver and limiting amplifier of each modulation subunit (310) is provided through a flex printed circuit board (114) .

9. The module (10) according to claim 7, wherein the connection between the PIC (210) and the respective laser driver and limiting amplifier of each modulation sub-unit (310) is provided through a rigid or flex interposer or connectivity circuit (can be among others, wire bond, flip chip bumps or balls, interposer circuit board, flex-printed circuit board) (211) .

10. The module (10) according to any of the previous claims, wherein the HSEI (112) is a forty-pin high speed electrical interface, being configured to provide connection to the SFP-DD transceiver host where the SFPDD- MPM is incorporated employing a port connector.

11. The module (10) according to claim 10, wherein the port connector is comprised by a plurality of pins, andwherein the microcontroller (311) further comprises memory means adapted to store a memory pin map of the port connector; the microcontroller (311) being further programmed to select the pin function of each pin of the port connector based on the memory pin map; optionally, the port connector is comprised of forty pins.

12. The module (10) according to any of the previous claims, wherein the case (113) comprises at least one SC Hexa-BOSA / ferrule support (750) and at least a case spacer (760) to accommodate the installation of at least one Hexa-BOSA (110) or PIC (210) .

13. The module (10) according to claim 12, wherein the SC Hexa-BOSA / ferrule support (750) is made from a plastic material .

14. The module according to claim 12 or 13, wherein the case (113) further comprises:— a bottom (770) and a top (720) part;— one actuator tine (730) adapted to allow the extraction of the module (10) from the SFP-DD transceiver host's cage where it is incorporated;— a pull-tab (740) to allow a manual pull of the module (10) .

15. The module (10) according to claims 12 and 14 wherein the support (750) , the case spacer (760) , the bottom (770) and top (720) parts, the actuator tine (730) and the pull-tab (740) are made from metal; optionally the metal is zinc alloys, zamak 2, zamak 3, or aluminum.

16. The module (10) according to any of the previous claims, wherein the size of the case (113) isstandardized to fit within a receptacle cage of an SFP-DD transceiver host.

17. An SFP-DD transceiver host comprising at least one SFPDD-MPM optical module (10) according to any of the claims 1 to 16.

18. A 50G-PON-OLT comprising at least one SFP-DD transceiver host according to claim 17.

19. A XGS-PON-OLT comprising at least one SFP-DD transceiver host according to claim 17.

20. A GPON-OLT comprising at least one SFP-DD transceiver host according to claim 17.

21. A Multi-PON OLT comprising at least one SFP- DD transceiver host according to claim 17.

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