Hybrid optical in-line amplifiers and security on physical level December 7, 2018 A. Shipulin, F. Küppers, Center for Photonics and Quantum Materials, Moscow, Russia, phone: +7 919 784 8581, a.shipulin@skoltech.ru  

Content EDFA&Raman hybride amplifier Security on Physical Level (SPL) technology

Content EDFA&Raman hybride amplifier Security on Physical Level (SPL) technology

Broadwing All-Optical Intelligent Network Unmanned operation- automatic adjustment!!! San Francisco San Jose Santa Clara Fresno Modesto Hayward Sacramento Las Vegas Bakersfield Palmdale Los Angeles San Diego Salt Lake City Mountain View Laramie Cheyenne Denver Aurora Colorado Springs Bend Seattle Minneapolis Madison Milwaukee Chicago Indianapolis Greenwood Joplin Tulsa Pevely St. Louis Dayton Cincinnati Oklahoma City Dallas Ft. Worth Abilene Midland Waco Austin Smithville San Antonio McQueeny Corpus Christi McAllen Harlingen Reynosa Houston New Orleans Baton Rouge Jackson Clanton Birmingham Charlotte Greensboro Raleigh Richmond Washington, D.C. Columbus Jacksonville Daytona Beach Kansas City Orlando Tampa Miami Medley South Bend Toledo Kalamazoo Grand Rapids Pontiac Detroit Dearborn Ann Arbor Cleveland Youngstown Pittsburgh Akron Hudson Baltimore Philadelphia Trenton Newark DE Newark NJ New York Stamford New Haven Providence Boston Albany Syracuse Rochester Buffalo El Paso Tucson Phoenix Legend Systems (Area) Terminal Route Lit Junction Fiber Complete Switch Louisville Memphis Nashville Atlanta Saginaw Lansing Bay City Flint Tallahassee Oakland Boise Lubbock Albuquerque Shreveport Portland 19,000+ Miles of Fiber 500+ Customer Access Locations 140+ Major Network Access Points Network has been designed as a UNITED system

Broadwing All-Optical Intelligent Network Transmitter Receiver Amplifier Add-Drop mux 2.5 GHz (OC-48), 10 GHz (OC-192) Client port, Client port C-band plus optional uninterrupted upgrade to C+L 2,5 GHz/10 GHz channels, Manchester coding technique EDFA, Raman, and EDFA&Raman hybrid amplifiers Mesh all-optical all USA network All nodes communicate with each other – automatic adjustment!

C + L band loss compensation C - band L - band In a real fiber the losses are fiber type specific (SMF, DSF, TW-RS, LEAF, All-Wave) ! In a real fiber the losses in L band are fiber span specific !! In a real fiber losses are varying depends on environmental conditions – automatic gain adjustment is required !!!

EDFA & Raman hybrid amplifiers Compromise is in hybrid EDFA & Raman amplifiers EDFA first stage Raman co-pump GFF second stage counter-pump 1400 1500 1530 1565 1570 1605 C - band L - band pumps Raman Gain profile Raman Amplification better OSNR lower signal power less nonlinear effects longer propagation distance! Gain spectrum has to be flat +/- 3 dB in front of the receiver!

Mki are measured and stored for each span. Raman amplification P – pumps, S – signals i=1…10, k=1…100 1. Raman amplification is described by: for about 100 channels there are no more than 10 pumps Least Square Method Linearization is required. 2. Linearization can be done assuming that mutual pump to pump and signal to signal interactions are negligible: Mki are measured and stored for each span. Is it correct or not ???

Fiber specific approach Mki are measured and stored for each span. Raman Gain profile C - band L - band 1400 pumps 1500 1530 1565 1570 1605 Pi Gk Single pump, linear Pi,0 Gk,0

Gain Flattening Algorithm – experimental implementation The Least Square Method can be applied straightforward: Gain before adjustment Gain Error EDFA first stage GFF second stage Raman counter-pump The pumps minimizing Error Function are applied. The procedure is repeated periodically in order to adjust the deviations.

Gain Flattening Algorithm – nonlinear procedure 1400 1500 1530 1565 1570 1605 C - band L - band pumps Raman Gain profile Pi Gk Single pump, linear All pumps, nonlinear, working point Pi,0 Gk,0

Content EDFA&Raman hybride amplifier Security on Physical Level (SPL) technology

Information security protection. Security on Physical Level - SPL LINK Node “Alice” Node “Bob” Eve dropper Encryption Authentication SPL All-optical communication line can be compromised by tapping signal between nodes. SPL technique protects link against any types of attack.

Conventional 10Gb/s data spectrum Quadrature Manchester data spectrum Manchester coding Conventional 10Gb/s data spectrum Quadrature Manchester data spectrum We suggest to use instead of one, for example, 10 GHz channel – two 2x5 GHz sub-channels, which can be generated by the same quadrature modulator used for QPSK modulation. Physical separation can be done relatively easy with one extra block, fully compatible with the existent infrastructure. Each sub-channel does not carry any meaningful information, no frames etc. Being separated, each sub-channel can be tapped, but information can not be recovered.

Link with two extra SPL blocks Demonstration of time delay between subcarriers introduced by SPL-Tx that is compensated back by SPL-Rx for successful signal receiving and interpretation. Red and blue peaks show two sub-channels A and B in spectrum and time domains. “LINK” stands for either the same path, or different paths for two sub-channels. N1 N2 N3 N4 A B Example of a mesh network with four nodes N1, N2, N3, and N4.

SPL protection technology: SPL_Tx block 50/50 Out A+B A ISO 99/1 B FBG Monitor A, 1% SPL-Tx in OS Out A, 99% Monitor B, 1% Out B, 99% Monitor A+B Time delay between sub-channels Optional external delay line – security key SPL-Tx block. Optical signal A+B is subdivided by a circulator and a FBG. Sub-channel A propagates through the upper, while B – through the lower side of SPL-Tx. After that both signals are separated in time using the appropriate delay line in one and/or another arm. For the point to point operation mode, OSs (Optical Switchers) send signals to 99/1 couplers, while for the mesh network operation mode – to 50/50 coupler. For unsecured operation mode (both single 10 GHz channel or 2x5 GHz channels), OS at the input sends signal through the lower path without any modifications.

SPL technology: advantages Compatibility with all existing fiber optic communication network infrastructure. Classical operational principles which (in contrast with the quantum security technology) make SPL compatible with non-coherent amplification and other all- optical system technologies. Flexibility in terms of different modulation formats: SPL technology is compatible with non-coherent like NRZ, RZ, and coherent like DP-QPSK etc. modulation formats. Moreover, the same hardware can be designed to provide all necessary modulation formats with SPL and could be dynamically reconfigurable to provide different modulation formats depends on current requirements. SPL technology does not require major changes in system operation: it requires only one extra block on transmitter and receiver sides, which makes this technology commercially much more attractive in compare with the quantum operation based security.

Thanks for your attention! Conclusion Thanks for your attention!