Phase-Sensitive Fiber Optic Parametric Amplifier and Their Applications in Optical Communications

This thesis deals with experimental and theoretical aspects of the phase-sensitive fiber optic parametric amplifier (FOPA) and their applications. FOPAs can be oper- ated as both phase-insensitive and phase-sensitive amplifiers (PSAs), with the latter requiring phase-locked input waves, which, until recently, has limited their practi- cal use. Based on the realization that a phase-insensitive FOPA, called the copier, can generate the phase-locked waves required, several applications of a copier-PSA configuration are proposed and demonstrated. These include phase excursion ampli- fication, ultra-low noise amplification, and, by using the copier for carrier recovery, black-box all-optical phase- and amplitude regeneration. A large part of this thesis deals with characterization of the PSA. The copier-PSA configuration is useful in this regard, since, by modulating the signal in between the copier and PSA, the phase-response of the PSA can be studied. The output signal was investigated both in terms of amplitude and phase, using a coherent receiver. Finally, methods to suppress stimulated Brillouin scattering (SBS) in HNLFs are investigated. Without suppression, SBS will severely limit the available pump power for parametric amplification. The most common way to suppress the SBS is to increase the spectral width of the pump, but this is undesirable in many ap- plications, including phase-sensitive amplification. Therefore, the application of a strain gradient to the fibers to decrease the SBS is studied. However, such a gradi- ent also introduces an undesired dispersion variation, and this trade-off is evaluated as well. A cascade of HNLFs with strain gradients, separated by low-loss and low- dispersion isolators is proposed and evaluated, with a large increase in the SBS threshold demonstrated

Phase-to-phase and phase-to-amplitude transfer characteristics of a nondegenerate-idler phase-sensitive amplifier

For the first time to our knowledge, the phase-to-phase and phase-to-amplitude transfer functions of a nondegenerate-idler phase-sensitive fiber optic parametric amplifier are experimentally measured. Additionally, analytically and numerically obtained transfer curves show excellent agreement with the experimental curves. The experimental results were obtained by imposing a linear phase modulation onto the signal and idler wave simultaneously, and detecting the input and output signal using a self-homodyne coherent receiver

Long-Haul (3465 km) Transmission of a 10 GBd QPSK Signal with Low Noise Phase-Sensitive In-Line Amplification

We report the first use of low noise in-line phase-sensitive amplifiers in a long-haul circulating loop experiment. A reach extension of 200% compared to using EDFAs is observed with a 10 GBd QPSK signal

Demonstration of Degenerate Vector Phase-Sensitive Amplification

The performance of a degenerate vector (dual cross-polarized pump) phase-sensitive amplifier (PSA) is characterized and compared to a degenerate scalar (dual co-polarized pump) PSA. In both schemes, we assess the gain as a function of the signal state of polarization, verifying its compliance with theory, and the phase transfer function

Noise performance of a frequency nondegenerate phase-sensitive amplifier with unequalized inputs

For the first time to our knowledge, the noise performance of a frequency nondegenerate phase-sensitive amplifier (PSA) with unequalized input powers has been experimentally characterized, based on a fiber-based parametric copier-PSA scheme. Two different noise-figure (NF) definitions-separate and combined NFs-are provided and compared. The results show that the separate NF of the weaker input wave is lower than that of the stronger wave due to the correlated-light nature. When considering the combined NF, the optimal noise performance (0 dB NF) is obtained only when the input powers are equal. Experiments agree well with the theoretical predictions. (C) 2011 Optical Society of Americ

Investeringskalkyl för AB Karl Hedin

Detta är en rapport om investeringskalkylering inom ett sågverk. För att bäst få insikt i hur investering fungerar ur ett ekonomiskt perspektiv, har ett praktiskt fall hos AB Karl Hedins sågverk Karbenning kalkylerats. Konkurrensen inom sågverksindustrin är idag stor. Därför krävs det ingående kalkyler angående investeringar, för att på bästa sätt kunna möta konkurrensen och hålla god lönsamhet. Målet med rapporten är att analysera lönsamheten för en investering i en brädscanner på Karbenning sågverk, utifrån givna data. Studien undersöker hur utfallet påverkas av vissa faktorer. Dessa faktorer är grundinvesteringens storlek, kalkylränta, restvärde, ekonomisk livslängd, drifts- och underhållskostnader samt betalningsöverskott. För att lösa uppgiften användes nuvärdemetoden. Denna metod går ut på att man diskonterar framtida intäkter och kostnader rörande investeringen dagens värde. Då erhålls ett nettonuvärde som vid ett värde av noll eller större indikerar på en lönsam investering. Ingångsdata har erhållits från AB Karl Hedin, samt deras underleverantörer. Beräkningarna utfördes i Excel. Resultatet blev att investeringen var mycket lönsam, med erhållna ingångsdata. För att veta hur känslig kalkylen är för investeringar gjordes en känslighetsanalys på variabler som kan tänkas påverka resultatet, exempelvis kalkylränta, besparingar, kostnader. Någon variabel som i högre grad påverkar investeringens lönsamhet kunde inte finnas. Investeringen är lönsam även om förutsättningarna ändras avsevärt. Investeringskalkylering är ett traditionellt sätt att skapa ett underlag för beslut om investering.This is a report about investment calculation at a saw mill. To gain insights on how investments are evaluated, a practical case at AB Karl Hedin sawmill Karbenning was analysed. Competition in the sawmill industry is now hard. It requires extensive calculations on investment to meet the competition in the best way and stay profitable. The objective of the report is to analyse the profitability of an investment in board scanner on Karbenning sawmill, from given data. The study also examines how the outcome is affected by certain factors. These factors are the size of the basic investment value, discount rate, residual value, useful life, operating- and maintenance expenses and payments surpluses. To solve the task, the net present value method is used. According to the method future revenues and costs related to the investment are discounted to the present value. Then the net present value at a value greater than zero indicates a profitable investment. The input data were obtained from AB Karl Hedin, and their suppliers. Calculations were carried out in Excel. The result shows that the investment was highly profitable, with the resulting input data. A sensitivity analysis on variables that could affect the outcome, such as cost of capital, savings and costs, was done. Any variable that affects the profitability of the investment in a greater extent could not be found. The investment is profitable even if the conditions are changed considerably. Investment calculation is a traditional way to create a basis for decisions on investment

Mask testing of 28 gbaud 16-QAM transmitters using time-resolved error vector magnitude

We propose time-resolved EVM for characterization of 16-QAM transmitters. By designing a mask test, different impairments can be separated and quantified. The impact from quadrature error and timing skew are investigated experimentally

Phase-Sensitive Optical Pre-Amplifier Implemented in an 80km DQPSK Link

We present the first demonstration of a phase-sensitive fiber optic parametric amplifier successfully implemented over an 80 km dispersion managed link. We measure 1.3 dB higher sensitivity with this amplifier system against a comparable conventional EDFA-based link

Phase-Sensitive Amplification of 28 GBaud DP-QPSK Signal

We demonstrate, for the first time, amplification of a DP-QPSK signal using a vector phase-sensitive amplifier (PSA). The PSA-based receiver shows an about 0.7 dB sensitivity improvement compared to an EDFA-based receiver

Experimental analysis of degenerate vector phase-sensitive amplification

We comprehensively investigate a degenerate vector phase-sensitive amplifier (PSA). We determine the gain dependence on the relative phase and polarization angle between the pumps and the degenerate signal wave. The vector PSA is experimentally shown to be sensitive to the pump states of polarization (SOP) due to polarization mode dispersion in the fiber. However, the scheme performance agrees well with theory under specific pump SOPs and we achieve an on-off gain over 10 dB with a small deviation from the theoretically expected results. In comparison to the scalar scheme, the proposed vector scheme has larger tolerance for pump depletion due to four-wave mixing between pumps and generation of higher-order idlers