EP4639803A1

EP4639803A1 - A burst mode optical limiting amplifier

Info

Publication number: EP4639803A1
Application number: EP23837553.9A
Authority: EP
Inventors: Cláudio Emanuel GOMES FERREIRINHO LIMA RODRIGUES; Alfonso Carlos ANTERO MAIA FIGUEIREDO; Francisco Manuel RUIVO RODRIGUES; Carla RODRIGUES
Original assignee: Picadvanced SA; Altice Labs SA
Current assignee: Picadvanced SA; Altice Labs SA
Priority date: 2022-12-19
Filing date: 2023-12-19
Publication date: 2025-10-29
Also published as: PT118412A; WO2024132209A1

Abstract

The present invention relates to a Burst Mode Optical Limiting Amplifier (BMOLA), projected to work as a burst mode amplifier of a Burst mode receiver and to be incorporated in any state-of-the-art receiver of an optical transceiver for PON OLTs supporting XGS-PON and/or 25GS-PON and/or 50G-PON Small Form-Factor Pluggable modules.

Description

DESCRIPTION

A BURST MODE OPTICAL LIMITING AMPLIFIER

FIELD OF THE INVENTION

The present invention is enclosed in the area of passive optical networks (PON) , 10 Gigabit-capable symmetric passive optical network (XGS-PON) , 25 Gigabit symmetric passive optical network (25GS-PON) , and Higher speed passive optical networks (HSPON) , 50G-PON, and optical line terminals (OLT) , particularly in the field of burst mode optical receivers.

PRIOR ART

Passive Optical Networks have 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) PON-OLTs commonly use burst mode receivers (BMRs) hosted in small form pluggable (SFPs) configurated for carrying out the reception of the passive optical network (PON) data-based on Time Division Multiple Access (TDMA) .

In conventional BMRs, the optical signal is detected by a photodiode and amplified by a transimpedance amplifier (TIA) . In a multipoint system, such as PON, based on Time Division Multiple Access (TDMA) , the optical network Terminals (ONTs) are at different distances, experiencing different losses resulting in different optical amplitudes on the Optical Line Terminal (OLT) receiver, and therefore, different packet amplitudes. The decision threshold used in the detector for electrical amplification and digital level restoration must be modified from burst to burst, hence it is difficult to recover the amplitudes and phases of the

RECTIFIED SHEET (RULE 91) ISA/EP incoming burst packets within a very short time. For this reason, state-of-art OLT burst mode optical receivers use a reset signal to reset the TIA in each incoming burst to recover amplitudes and phases.

When a PON system is migrated from legacy PON to new PON systems, this is, XGS-PON, 25GS-PON, and 50G-PON, there can be several approaches, which are OLT Multi-PON modules and external wavelength division multiplexing. This approaches, where the fiber network distances and losses can be increased lead the new PON BMR to be able to deal with higher PON losses than in the legacy PON.

PROBLEM TO BE SOLVED

Current BMR for PON optical transceiver modules for XGS-PON, 25GS-PON, or 50G-PON require large bandwidth optical receivers, fast response TIAs, capable of high attenuation ranges, and very low sensitivities at low bit error rates. The present invention addresses the above problem.

SUMMARY OF THE INVENTION

The present invention relates to a Burst Mode Optical Limiting Amplifier (BMOLA) , projected to work as a burst mode amplifier of a BMR and to be incorporated in any state-of-the-art receiver of an optical transceiver for PON OLTs supporting XGS-PON and/or 25GS-PON and/or 50G-PON.

Due to the set of technical features that characterize the BMOLA developed, it is possible to increase the sensitivity of a BMR on a PON transceiver.

RECTIFIED SHEET (RULE 91) ISA/EP DESCRIPTION OF FIGURES

Figure l is a schematic diagram of the BMOLA module developed to be integrated into a BMR for a PON transceiver, according to certain aspects of the invention . The numerical references represent :

10 - BMOLA;

20 - BMOLA photonic integrated circuit ;

110 - Burst mode TIA;

111 - Optical receiver ;

112 - Semiconductor Optical Ampli fier ( SOA) ;

113 - Sensing optical receiver;

114 - Current comparator and current generator;

115 - Reset controller ;

116 - Reset line ;

117 - Receiver data lines ;

Figure 2 is a schematic diagram of the BMOLA photonic integrated circuit ( 20 ) according to certain aspects of the invention . The numerical references represent :

111 - PIN or APD Optical receiver ;

113 - PIN or APD Sensing optical receiver ;

200 - WDM passive filter with add-drop filter, optical splitter, and integrated SOA;

201 - optical coupling receptacle ;

202 - fiber;

203 - V-groove ;

204 - PON upstream add-drop filter;

205 - optical splitter ;

206 - lenses or photonic wire bonds ;

207 - lenses or photonic wire bonds ;

208 - lenses or photonic wire bonds ;

209 - interposer, wire bond, or simple deposited electrical waveguides and pads ;

RECTIFIED SHEET (RULE 91) ISA/EP 210 - holder ;

211 - interposer, wire bond, or simple deposited electrical waveguides and pads ;

212 - interposer, wire bond, or simple deposited electrical waveguides and pads ;

213 - light source;

214 - interposer, wire bond, or simple deposited electrical waveguides and pads

Figure 3 illustrates the signals behavior of the BMOLA module developed and integrated into a BMR for a PON transceiver according to certain aspects of the invention . The numerical references represent :

30 - semiconductor optical ampli fier optical input ;

31 - sensing optical receiver reset ;

32 - sensing optical receiver current ;

33 - semiconductor optical ampli fier reset ;

34 - semiconductor optical ampli fier input current ;

35 - semiconductor optical ampli fier optical output/ input of burst mode optical receiver;

36 - burst mode optical receiver reset ;

37 - burst mode optical receiver electrical output ;

DETAILED DESCRIPTION

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

The present invention relates to a BMOLA, proj ected to work as a burst mode amplifier of a BMR and to

RECTIFIED SHEET (RULE 91) ISA/EP be incorporated in any state-of-the-art receiver of an optical transceiver for PON OLTs supporting XGS-PON and/or 25GS-PON and/or 50G-PON

According to the main embodiment of the invention, the BMOLA (10) is comprised of at least a BMOLA photonic integrated circuit (20) , a burst mode TIA (110) , a current comparator, and a current generator (114) , a reset controller (115) and high-speed electrical interfaces as receiver data paths (117) and reset line (116) . These elements comprising the BMOLA (10) are housed in a case that is to be installed inside the SFP transceiver as part of the receiver of an XGS-PON, 25GS-PON, or 50G-PON OLT .

The BMOLA photonic integrated circuit (20) is comprised of a least a semiconductor optical amplifier (112) , an optical receiver (111) , and a sensing optical power receiver (113) .

Figure 2 is the schematic diagram of the BMOLA photonic integrated circuit (20) package. The BMOLA photonic integrated circuit (20) package comprises a holder (210) which has a V-groove (203) for connecting a fiber (202) which holds an optical coupling receptacle (201) . This holder (210) has also the function of allowing hybrid assembling of the different devices, keeping them together and aligned. In Figure 2, (200) is a WDM passive filter with an add-drop filter (204) shaped to meet the required technology, which in an instantiation, can be 50G-PON downstream or XGS-PON downstream or 25GS-PON downstream whose characteristics can be obtained from each of the standards. (200) holds monolithically the receivers (111 and 113) , the PON transmitter (213) , and the connection to the WDM filter (204) . (206 to 208) are lenses or photonic wire bonds which connect to each of the discrete devices, serving as an interface for the photonic path. (Ill and 113) are external receivers, which can be instantiated as PINs or APDs, which

RECTIFIED SHEET (RULE 91) ISA/EP are connected electrically through an interposer, wire bond, or simple deposited electrical waveguides and pads (209, 211, and 212) . (112) is a semiconductor optical amplifier integrated into the WDM passive filter (200) which is driven through the electrical connections (214) (interposer, wire bond, or simple deposited electrical waveguides and pads) to the external drivers. (115) is an optical splitter integrated into the WDM passive filter (200) to provide the signal to the PIN or APD Optical receiver (111) and the SOA (112) .

Figure 3 illustrates the necessary signals behavior of the BMOLA according to the invention. As the burst mode optical signals from the optical network units arrive at the BMOLA (30) the sensing optical receiver (113) will detect the mean amplitude of the optical input signals and will generate a current (32) , this current is injected in the current comparator (114) and by comparison will generate the necessary input current (34) to the SOA (112) to amplify the burst mode optical input signals (30) . The current comparator and current generator (114) are designed in a way, where less current received from the sensing optical receiver (113) will generate more current (34) to the SOA (112) . This current comparator and current generator (114) has also a maximum limited current to not generate too much gain on SOA and very high SOA output optical power (35) for not causing saturation of the optical receiver (111) .

The reset line (116) , coming from OLT, used on current state-of-art PON OLTs to reset burst mode TIA receivers is used in BMOLA by the reset controller (115) to perform several functions, namely, reset (31) sensing optical receiver (113) , allowing the sensing optical receiver to be ready for next burst mode optical input signal (30) , reset (33) SOA (112) input current (34) , allowing the SOA (112) to be ready for amplification of next burst mode

RECTIFIED SHEET (RULE 91) ISA/EP optical input signal (30) and as in current state-of-art PON OLTs to reset (36) the burst mode TIA (110) .

The BMOLA (10) optical receiver (111) for 50G-PON upstream is a three-rate burst mode receiver and burst mode TIA (110) working on the 50G-PON upstream wavelength at 12.44 Gbit/s, 24.88 Gbit/s, and 49.76 Gbit/s. The BMOLA (10) optical receiver (111) for 25GS-PON is a dual-rate burst mode receiver and burst mode TIA (110) working on the 25GS- PON upstream wavelength at 12.44 Gbit/s and 24.88 Gbit/s. The BMOLA (10) optical receiver (111) for XGS-PON is a dualrate burst mode receiver and burst mode TIA (110) working on the XGS-PON upstream wavelength at 2.48 Gbit/s and 9.95 Gbit/s.

The BMOLA (10) developed may be incorporated into an SEP transceiver of an XGS-PON, 25GS-PON, and 50G-PON OLT .

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.

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

RECTIFIED SHEET (RULE 91) ISA/EP

Claims

1. A Burst Mode Optical Limiting Amplifier (10) characterized for comprising:

— A BMOLA photonic intgrated circuit (20) ;

— A burst mode TIA (110) ;

— An optical receiver (111) ;

— A sensing optical receiver (113) ;

— A current comparator and current generator (114) ;

— A reset controller ( 115) ;

— high-speed electrical interfaces, and receiver data lines ( 117 ) .

2. The BMOLA (10) according to to claim 1, characterized for comprises:

— a BMOLA photonic integrated circuit (20) package comprised of at least a semiconductor optical amplifier (112) , an optical receiver (111) , and a sensing optical power receiver (113) , to amplify and receive burst mode optical signals.

3. The BMOLA (10) according to claim 2, characterized for further comprising:

— a three-rate burst mode receiver and burst mode

TIA (110) working on the 50G-PON upstream wavelength at 12.44 Gbit/s, 24.88 Gbit/s, and 49.76 Gbit/s, or,

— a dual-rate burst mode receiver adapted to operate on the 25GS-PON upstream wavelength at

12.44 Gbit/s Gbit/s and 24.88 Gbit/s; or — a dual-rate burst mode receiver adapted to operate on the XGS-PON upstream wavelength at 2.48 Gbit/s and 9.95 Gbit/s.

4. A BMOLA photonic integrated circuit (20) characterized for comprising:

— a holder (210) which has a V-groove (203) for connecting a fiber (202) which holds an optical coupling receptacle (201) ; and

— which has the function of allowing the hybrid assembling of different devices keeping them together and aligned;

— a WDM passive filter (200) , designed in a photonic integrated circuit to meet the requirements of mounting and coexisting the transmission and reception of, 50G-PON, XGS- PON, and 25GS-PON;

— a waveguide to integrated PIN or APD (111 and 113) ;

— lenses or photonic wire bonds (206 to 208) which connect to each of the discrete devices, serving as an interface for the photonic integrated circuit ;

— optical source (213) which can be intrinsically directly modulated lasers, externally modulated lasers, or continuous wave;

— an SOA (112) to amplify the burst mode optical signals ;

— an optical splitter integrated into the WDM passive filter (200) to provide the signal to the PIN or APD Optical receiver (111) and the SOA (112) . — Electrical connections (interposer, wire bond, or deposited electrical waveguides and pads) (209, 211,212,214) ;

5. A reset line (116) used in BMOLA by the reset controller (115) characterized for comprising: reset (31) sensing optical receiver (113) , allowing the sensing optical receiver to be ready for the next burst mode optical input signal (30) ; reset (33) SOA (112) input current (34) , allowing the SOA (112) to be ready for amplification of the next burst mode optical input signal (30) and; to reset (36) the burst mode TIA (110) .

6. A current comparator and current generator (114) characterized for comprising, less current received from the sensing optical receiver (113) generate more current (34) to the SOA (112) ;

- maximum limited current to not generate too much gain on SOA and very high SOA output optical power (35) for not causing saturation of the optical receiver (111) .

7. The Burst Mode Optical Limiting Amplifier (10) module (10) according to any of the previous claims 1 to 6, characterized for being incorporated in any state-of-the-art receiver of an optical transceiver for PON OLTs supporting XGS-PON and/or 25GS-PON and/or 50G-PON.

8. BMOLA photonic integrated circuit (20) characterized for comprising an add-drop filter (204) shaped to meet the required technology that can be 50G-PON downstream or XGS-PON downstream or 25GS-PON downstream.

9. BMOLA photonic integrated circuit (20) characterized for comprising an add-drop filter (204) and a holder for a PON transmitter (213) that can be 50G-PON downstream or XGS-PON downstream or 25GS-PON downstream.

10. Burst Mode Optical Limiting Amplifier (10) characterized for comprising the amplification of upstream 25GS-PON signals.

11. Burst Mode Optical Limiting Amplifier (10) characterized for comprising the amplification of upstream XGS-PON signals.

12. Burst Mode Optical Limiting Amplifier (10) characterized for comprising the amplification of upstream 50G-PON signals.