* The only book describing applications of nonlinear fiber optics * Two new chapters on the latest developments: highly nonlinear fibers and quantum applications* Coverage of biomedical applications* Problems provided at the end of each chapterThe development of new highly nonlinear fibers - referred to as microstructured fibers, holey fibers and photonic crystal fibers - is the next generation technology for all-optical signal processing and biomedical applications. This new edition has been thoroughly updated to incorporate these key technology developments.The book presents sound coverage of the fundamentals of lightwave technology, along with material on pulse compression techniques and rare-earth-doped fiber amplifiers and lasers. The extensively revised chapters include information on fiber-optic communication systems and the ultrafast signal processing techniques that make use of nonlinear phenomena in optical fibers.New material focuses on the applications of highly nonlinear fibers in areas ranging from wavelength laser tuning and nonlinear spectroscopy to biomedical imaging and frequency metrology. Technologies such as quantum cryptography, quantum computing, and quantum communications are also covered in a new chapter.This book will be an ideal reference for: RD scientists involved with research on fiber amplifiers and lasers; graduate students and researchers working in the fields of optical communications and quantum information. * The only book on how to develop nonlinear fiber optic applications* Two new chapters on the latest developments; Highly Nonlinear Fibers and Quantum Applications* Coverage of biomedical applications

Applications of nonlinear fiber optics

In Ethiopia, food production for a rapidly growing population from a continually shrinking farm size is a prime developmental challenge. Rising input costs, decline in soil quality, and buildup of insect pests, diseases and weeds have threatened the ecological and economic sustainability of crop production. To address those issues, intercropping of cereals with pulse crops could increase total grain production, provide diversity of products, stabilize yield over seasons, reduce economic and environmental risks common in monoculture systems, and thereby enhance sustainability. Here, mixed intercropping of wheat (Triticum aestivum L.) with faba bean (Vicia faba L.) was compared with sole culture of each species in 2002 and 2003 at Holetta Agricultural Research Center, in the central highlands of Ethiopia. The treatments were sole wheat at a seed rate of 175 kg ha −1 , sole faba bean at a seed rate of 200 kg ha −1 , and an additive series of 12.5, 25, 37.5, 50 and 62.5% of the sole faba bean seed rate mixed with the full sole wheat seed rate. Our results showed that mixed intercropping increased the land equivalent ratio by +3% to +22% over sole cropping. Increasing the faba bean seed rate in the mixture from 12.5 to 62.5% reduced wheat grain yield from 3601 kg ha −1 to 3039 kg ha −1 but increased faba bean grain yield from 141 kg ha −1 to 667 kg ha −1 . Sole culture grain yield exceeded mixed culture grain yield by + 5t o+25% for wheat and by +172 to +1190% for faba bean. Nonetheless, we obtained the highest total grain yield of 4031 kg ha −1 , gross monetary value of US$ 823, system productivity index of 4629 and crowding coefficient of 4.70 when wheat at its full seed rate was intercropped with faba bean at a rate of 37.5%. On average, weed biomass was reduced from 40.4 g m −2 in sole wheat to 31.1 g m −2 in mixed culture and the chocolate spot disease score was reduced from 5.1 in sole faba bean to 3.4 in mixed culture. In conclusion, intercropping of wheat with faba bean may increase total yield and revenue, reduce weed and disease pressure, increase land-use efficiency, and thereby enhance sustainability of crop production in Ethiopian highlands. aggressivity / crowding coefficient / faba bean / land-use efficiency / intercropping / wheat

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Yield potential and land-use efficiency of wheat and faba bean mixed intercropping

An efficient gain-flattened L-band optical amplifier is demonstrated using a hybrid configuration with a distributed Raman amplifier (DRA) and an erbium-doped fiber amplifier (EDFA) for 160 × 10-Gb/s dense wavelength division multiplexed system at 25-GHz interval. With an input signal power of 3 mW, a flat gain of >; 10 dB is obtained across the frequency range from 187 to 190.975 THz with a gain variation of ; 8.9 dBm) ever reported for a DRA-EDFA hybrid optical amplifier at reduced channel spacing.

Flat-Gain L-Band Raman-EDFA Hybrid Optical Amplifier for Dense Wavelength Division Multiplexed System

For the first time, a novel flat-gain optical amplifier is proposed using a hybrid configuration with an Er-Yb co-doped waveguide amplifier (EYDWA) and a semiconductor optical amplifier (SOA) for 100 × 10-Gb/s dense wavelength division multiplexed system at 0.2 nm interval. With an EYDWA-SOA hybrid amplifier, a flat gain of is obtained across the effective bandwidth with a gain variation of the order of 0.75 dB without using any gain clamping techniques. It is observed that when the proposed hybrid amplifier is used as a booster for hybrid distributed Raman amplifier and erbium doped fiber amplifier, the gain variation is reduced from 2.01 to ~ 1.15 dB efficiently with acceptable bit error rate.

Novel Optical Flat-Gain Hybrid Amplifier for Dense Wavelength Division Multiplexed System

\n This study clarifies the comparison between hybrid all optical fiber amplifiers in single-stage and multi-stage amplification. EDFA/Raman, Raman/EDFA/Raman, and EDFA/Raman/EDFA configurations are employed for upgrading optical communication systems. Single-stage Raman amplifiers clarifies very better performance than single-stage EDFA amplifier. Multi-stage Raman/EDFA/Raman also outlines very better performance than other hybrid configuration up to 475 km distance. Single-stage Raman amplification has outlined maxi. Q factor up to 218.392 for 250 km distance and 11.937 up to 475 km propagation range. So hybrid all optical amplifiers are essentially for upgrading optical system performance efficiency.

Comparative Simulation Study of Multi Stage Hybrid All Optical Fiber Amplifiers in Optical Communications

Power transience in an optical network hinders the performance of an optical communication system. In addition to increasing the capacity of the system, it has become mandatory to decrease fiber losses so as to increase the total efficiency of the system. Power transience is one such loss which not only decreases the efficiency of the system but also poses a threat to the functioning of active components. In this paper, we propose and exemplify the concept of recycling residual pumping in a Raman–erbium-doped fiber (EDF) hybrid optical amplifier (HOA) in the scenario of a dense wavelength division multiplexed (DWDM) system. Further, we investigated the power transience in the proposed hybrid amplifier and control it by using power shaping and channel shaping techniques.

Performance investigation of hybrid optical amplifier using recycled residual pumping

This paper presents the conceptual behavior of digital communication for the composite Rician-Two Wave Diffuse Power (TWDP) fading-shadowing model. Here, small scale fading is attributed by the Rician channel, whereas shadowing effects are modeled by TWDP. More specifically, in this work the exact closed-form expression is derived for the probability density function (PDF), cumulative distribution function (CDF), joint moments, mean, variance, amount of fading (AF) and outage probability. Also, the effects of various shadowing parameters on system performance have been studied in detail. The obtained results are matched cum verified with special case results available in the literature and simulation results. 

Performance Analysis of Digital Communications over Rician-TWDP Channels

The synergistic influence of synthesized MoS2 (syn-MoS2) nanosheets and NaYF4:Yb,Tm,Nd upconversion nanoparticles (UCNP) on effective dye degradation is demonstrated. A detailed characterization of bulk MoS2 (b-MoS2), syn-MoS2 (with enhanced photocatalytic activity compared to the commercially available b-MoS2), and UCNP was done. Optical properties revealed that emission spectra of UCNP corresponding to 450, 475, and 650 nm overlap with absorption spectra of MoS2 (∼455 and 635 nm). A comparative methylene blue degradation of 96% could be achieved with the combination of UCNP and syn-MoS2 in comparison to 56.4% for syn-MoS2 and 42% for b-MoS2. Concentration-dependent dye degradation study of UCNP and syn-MoS2 revealed a maximum dye removal efficiency of 99.6% for 150 mg L–1 of syn-MoS2 and 200 mg L–1 of UCNP within 2 hrs. Comparative degradation investigations were performed on various dyes (methylene blue, methylene orange, rhodamine B, and their mixture) and water systems (artificial river-water and artificial seawater) to assess the potential applicability of the system in environmental remediation. After five cycles of reusability studies, an efficacy of 88% dye removal was obtained. The mechanism behind this was investigated using the ESR and scavengers test, which confirmed that the primary radicals responsible for dye degradation were superoxide (•O2–) and hydroxyl (•OH). A comparative photocurrent experiment also verified that the presence of UCNP enhances the efficiency of the syn-MoS2 by 98% in the presence of visible light. 

Synergistic Effect of Yb3+, Tm3+, Nd3+ Doped NaYF4 Nanoparticles and MoS2 Nanosheets for Enhanced Photocatalytic Dye Degradation under Visible Light

In this research paper, a 2x 2 multiple input multiple output (MIMO) patch antenna for the S and C band application is designed. This work focuses on the design of triangular patch with L slot for multiple applications such as radar systems (surface ship radar, weather radar), medical, industrial heating, cordless phones, WLAN, IEEE 802.11a Wi-Fi wireless computer network etc. Two methods are applied to this antenna to improve the performances. The first method is by adding the L slot on the triangular patch of the antenna. The second method is by changing the parameters of the ground plane. The main motto is to design of this patch antenna which can provide lower return loss, better efficiency and performances for S band and C band applications. The proposed antenna is designed on Rogers RT 6202 (loss free) substrate with the thickness 1.52 mm, dielectric constant 2.94. The antenna has a size of 100 mm x 100 mm. Radiation efficiencies are obtained above 70% for all desired frequencies. The simulation of the designed antenna is done by using Computer Simulation Technologies (CST) STUDIO SUITE software.

Simranjit Singh

Papers

Performance investigation of hybrid optical amplifier using recycled residual pumping

Performance Analysis of Digital Communications over Rician-TWDP Channels

Synergistic Effect of Yb3+, Tm3+, Nd3+ Doped NaYF4 Nanoparticles and MoS2 Nanosheets for Enhanced Photocatalytic Dye Degradation under Visible Light

MIMO Triangular Patch Antenna for Multiple Applications

Tricolor lasers and optical angular momentum based visible light communication system