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Author

V Lakshmi Narayanan

Bio: V Lakshmi Narayanan is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Phase conjugation & Phase noise. The author has an hindex of 1, co-authored 4 publications receiving 6 citations.

Papers
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Proceedings ArticleDOI
03 Mar 2019
TL;DR: Noise transfer properties during the phase conjugation process in nonlinear SOA is evaluated by varying the OSNR of the input signal and OSNR retention is observed for both the signal and the conjugate.
Abstract: We experimentally evaluate the noise transfer properties during the phase conjugation process in nonlinear SOA by varying the OSNR of the input signal. OSNR retention is observed for both the signal and the conjugate.

5 citations

Proceedings ArticleDOI
29 Jul 2018
TL;DR: In this article, the authors demonstrate the generation of polarization insensitive phase conjugate of PM-QPSK signal in both input and output ports of SOA using partially degenerate four wave mixing with pump power of only 4 dBm.
Abstract: We experimentally demonstrate the generation of polarization insensitive phase conjugate of PM-QPSK signal in both input and output ports of SOA using partially degenerate four wave mixing with pump power of only 4 dBm.

1 citations

Proceedings ArticleDOI
05 May 2019
TL;DR: Polarization insensitive phase conjugation generation is experimentally demonstrated using a single pump in a nonlinear SOA for 10 GBaud PM-QPSK data in this article, where the influence of polarization transformation properties specific to signal-pump detuning conditions are established.
Abstract: Polarization insensitive phase conjugation generation is experimentally demonstrated using a single pump in a nonlinear SOA for 10 GBaud PM-QPSK data. The influence of polarization transformation properties specific to signal-pump detuning conditions are established. © 2019 The Author(s)
Book ChapterDOI
17 Feb 2022
TL;DR: In this article , the damage mechanism, damage assessment and repair techniques are discussed in detail in detail, and special interest has been shown to understand the damage mechanisms of the composites, and damage assessment of composites using non-destructive test (NDT).
Abstract: Composite materials are extremely essential for specialized applications such as the aerospace industry, military applications, general aviation, automotive, surface transport and sports equipment markets. Usage of composite materials naturally led to a demand to develop repair procedures. Several damages (cracks and dents) in composite products are easily analysed through the naked eye. Some of the damages are best analysed through appropriate non-destructive test (NDT) for structural applications. In this chapter, special interest has been shown to understand the damage mechanism of the composites, damage assessment of the composites using NDT, various types of damages, laminate and sandwich panel repairs and different categories of repair techniques in composites. Notably, the damage mechanism, damage assessment and repair techniques are discussed in detail in this chapter.
Book ChapterDOI
17 Feb 2022
TL;DR: A review of polymer composites for the aerospace application is presented in this paper , where the authors consolidate the various polymer composite composites investigated for aerospace application and compare them with conventional materials.
Abstract: In the last decade, progress in the development of aerospace materials has grown exponentially. Aerospace materials are subjected to extreme loads and radiation and the materials should be tolerant to it. Generally, alloys, such as magnesium alloy, aluminum alloy, nickel alloy and titanium alloy are used in aerospace structural and engine applications. Recently, however, polymer composite materials are gaining phenomenal interest as a replacement of for conventional materials in aerospace applications. This is due to better mechanical, thermal and anti-static properties, as well as corrosion resistance and low cost of the polymer composites. This review consolidates the various polymer composites investigated for the aerospace application.

Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors demonstrate the simultaneous compensation of both dispersion and nonlinear effects in a 100 km optical fiber link using optical phase conjugation of a 21 GB aud QPSK and 16QAM signal with nonlinear SOAs.
Abstract: We experimentally demonstrate the simultaneous compensation of both dispersion and nonlinear effects in a 100 km optical fiber link using optical phase conjugation of a 21 GB aud QPSK and 16QAM signal with nonlinear SOAs. Error-free performance is recorded for a launched power of up to 12 dBm, without any digital signal processing to compensate for distortions due to chromatic dispersion and nonlinear effects in fiber. The performance is verified for operation across the C-band.

11 citations

Journal ArticleDOI
TL;DR: This paper presents the quantitative measurement through an experimental test of 640 Gbps 16-QAM coherent-optical orthogonal frequency-division multiplexing (CO-OFDM) over 800 km optical fiber with mid-link optical phase conjugation (OPC) using highly nonlinear fiber (HNLF).
Abstract: This paper presents the quantitative measurement through an experimental test of 640 Gbps 16-QAM coherent-optical orthogonal frequency-division multiplexing (CO-OFDM) over 800 km optical fiber with mid-link optical phase conjugation (OPC) using highly nonlinear fiber (HNLF) The first focus is the OPC parameter optimization, including the optimization of HNLF length and signal/pump power that inputs into OPC Four different HNLFs, as the illustrative examples, are investigated The second focus is to investigate the effects of fiber dispersion, nonlinearity, and amplified spontaneous emission (ASE) noise on the long-haul transmission of 16-QAM CO-OFDM signal, and the OPC compensation efficiency The performance evaluation focuses on the conversion efficiency (CE), received signal constellation, Q-factor improvement, and bit error rate (BER) at the receiver end Such end-to-end performance evaluation is important because the 16-QAM CO-OFDM signal status is heterogeneous and the mitigation of transmission impairments to the signal is still unclear The OPC parametric optimization is achieved experimentally using commercially available HNLFs with different scenarios and the numerical results are interpreted in conjunction with simulations

2 citations

Journal ArticleDOI
TL;DR: The effectiveness of the SOA-based phase conjugator to improve the link budget with a 100 km standard single mode fiber link for 20 GHz coherent OFDM signals, with QPSK and 16QAM modulations and a corresponding net bit-rate of 40 Gbps and 80 Gbps respectively is experimentally demonstrated.
Abstract: We study the use of nonlinear semiconductor optical amplifier (SOA) for generating optical phase conjugate towards compensation of distortions in short distance optical fiber transmission due to Kerr nonlinearity and chromatic dispersion in coherent multi-carrier lightwave signals. We experimentally demonstrate the effectiveness of the SOA-based phase conjugator to improve the link budget with a 100 km standard single mode fiber link for 20 GHz coherent OFDM signals, with QPSK and 16QAM modulations and a corresponding net bit-rate of 40 Gbps and 80 Gbps respectively. Mid-span spectral inversion scheme is employed where the optical phase conjugate is generated through a partially degenerate four-wave mixing process in a nonlinear SOA. We demonstrate a bit error rate performance within $2\times 10^{-2}$ for an average launched power of up to 12 dBm (9 dBm) for QPSK (16QAM) coherent OFDM signals, in a 100 km fiber link. We also investigate the possible improvement in link budget using numerical simulation for 16QAM and 64QAM CO-OFDM signals with the proposed scheme.

2 citations

Proceedings ArticleDOI
05 May 2019
TL;DR: Polarization insensitive phase conjugation generation is experimentally demonstrated using a single pump in a nonlinear SOA for 10 GBaud PM-QPSK data in this article, where the influence of polarization transformation properties specific to signal-pump detuning conditions are established.
Abstract: Polarization insensitive phase conjugation generation is experimentally demonstrated using a single pump in a nonlinear SOA for 10 GBaud PM-QPSK data. The influence of polarization transformation properties specific to signal-pump detuning conditions are established. © 2019 The Author(s)