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Optical Amplifiers (optical + amplifier)

Distribution by Scientific Domains
Engineering64%
Polymers and Materials Science17%
Physics and Astronomy17%

Selected Abstracts

High-Gain Broadband Solid-State Optical Amplifier using a Semiconducting Copolymer,

ADVANCED MATERIALS, Issue 1 2009
Dimali Amarasinghe
A dilute fluorene copolymer produces enhanced optical amplification. High gain with 1000 times optical amplification and a long lifetime is achieve in only 1mm of the material, and exciton,exciton annihilation is suppressed. [source]

Characterization of uni-traveling carrier photodiodes for high-linearity and high-SNR applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2010
Andreas O. J. Wiberg
Abstract A typical uni-traveling carrier photodiode (UTC-PD) and a commercial PIN-PD are compared in the context of the analog performance at 10 GHz in a realistic noise environment. The behavior of the carrier-to-noise ratio (CNR), the linearity, represented by the third-order output intercept point (OIP3), and the spurious free dynamic range are studied as a function of photocurrent. We have found that the increment of the CNR is only minor because of excess noise of the amplifier, as an optical amplifier is used to reach high optical power. However, the OIP3 of the UTC-PD is substantially higher and increases with photocurrent, in contrast to the PIN-PD. Thus, even though the responsivity is lower, it is beneficial to use a UTC-PD to have superior dynamic range. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:984,987, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25055 [source]

Fiber Bragg grating sensor network based on code division multiple access using a reflective semiconductor optical amplifier

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2010
Jongkyung Ko
Abstract We propose a multiplexed fiber Bragg grating sensor network based on code division multiple access (CDMA) using a self-injection locked reflective semiconductor optical amplifier. The proposed system shows improved scanning time without requiring a tunable laser source or a Fabry-Perot filter. CDMA was used to separate each reflected sensor signal and it shows a high dynamic range of over 40°C and a crosstalk ratio of 27.7:1. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 378,381, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24913 [source]

DOP-tunable semiconductor fiber ring laser

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2009
Nian Fang
Abstract A novel laser with tunable and stable degree of polarization (DOP) is introduced. It consists of a polarization beam splitter (PBS) and a bidirectional semiconductor fiber ring, which is composed of a semiconductor optical amplifier (SOA), a polarization controller (PC) and a 2 × 2 wideband fiber coupler. By adjusting the PC or the injected current of the SOA, the time averaged DOP of the laser output varies optionally from 0.16 to 99%. Employing the bidirectional ring structure and PBS polarization combination method, DOP of the laser can be kept stable at any level in that range. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1669,1671, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24403 [source]

Multiwavelength source based on SOA and EDFA in a ring-cavity resonator

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2009
S. Shahi
Abstract A multiwavelength source incorporating a semiconductor optical amplifier (SOA) and a erbium-doped fiber amplifier (EDFA) in a ring-cavity configuration was demonstrated. The multiwavelength source was able to generate more than 13 channels at ,27 dBm and above at a SOA bias current of 300 mA and 980-nm pump power of 92 mW. The number of wavelengths generated can be controlled by adjusting the birefringence of the ring cavity using the polarization controllers. The proposed laser has constant channel spacing of 0.8 nm, which is suitable for communication and sensing applications, and shows stable operation at room temperature. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 110,113, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23970 [source]

Linear optical amplifier-based semiconductor fiber ring laser with 93-nm tuning range

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2008
K. K. Qureshi
Abstract We propose a simple configuration of a traveling wave tunable semiconductor fiber ring laser. The proposed laser can be tuned over 93 nm with an output power of 1.3 dBm using a thin film fiber Fabry Pérot filter. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1702,1704, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23469 [source]

New Optical Amplifier Placement Schemes for Broadcast Networks

EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 1 2000
Jason Iness
WDM optical broadcast networks (based on the passive-star coupler) may encounter large splitting and attenuation losses that need to be compensated for using optical amplifiers, such as EDFAs. However, optical amplifiers are costly, so their total count in the network should be minimized. This study will examine three different such amplifier-placement schemes. The first approach utilize fewer amplifiers than previous schemes that do not add special hardware to avoid the near-far effect. The second study considers a bidirectionai-link network and it can use fewer amplifiers than a comparable unidirectional-link network. The third study minimizes the number of amplifiers when the amplifiers are equipped with special hardware to avoid the near-far effect, i.e., amplifiers are equipped with attenuators/filters to equalize amplifier input power on different wavelengths. [source]

Ligand-Driven Wavelength-Tunable and Ultra-Broadband Infrared Luminescence in Single-Ion-Doped Transparent Hybrid Materials

ADVANCED FUNCTIONAL MATERIALS, Issue 13 2009
Shifeng Zhou
Abstract Here, tuning of the optical properties of emission centers by tailoring the ligand fields is investigated. Experimentally, it is demonstrated that Ni2+ can act as a single emission species in multiple octahedral local environments. Nanocrystal-embedded hybrid materials are employed as hosts in order to take advantage of their convenience in local environment design for practical applications. Novel composite gain materials with high transparence are successfully made, and show interesting wavelength-tunable and ultra-broadband infrared luminescence covering the whole near-infrared region from 1,100 to 1,800,nm. The infrared luminescence peak positions can be finely tuned from 1,300 to 1,450 and to 1,570,nm, with the largest full width at half maximum being about 400,nm and covering the telecommunication bands at 1,200,1,500,nm. According to the results of characterization, the unusual luminescence, interestingly, originates from Ni2+ in nanocrystals and the doping efficiency of Ni2+ is surprisingly high. The results demonstrate that the method presented may be an effective way to fabricate multifunctional light sources with various fundamental multifunctional applications from efficient broadband optical amplifiers to bio-imaging. [source]

A New Sol,Gel Material Doped with an Erbium Complex and Its Potential Optical-Amplification Application,

ADVANCED FUNCTIONAL MATERIALS, Issue 6 2005
L.-N. Sun
Abstract The crystal structure of a ternary Er(DBM)3phen complex (DBM,=,dibenzoylmethane; phen,=,1,10-phenanthroline) and its in-situ synthesis via a sol,gel process are reported. The infrared (IR), diffuse reflectance (DR), and fluorescence spectra of the pure complex and the Er3+/DBM/phen co-doped luminescent hybrid gel, formed via an in-situ method (ErDP gel), have been investigated. The results reveal that the erbium complex is successfully synthesized in situ in the ErDP gel. Excitation at the maximum absorption wavelength of the ligands resulted in the typical near-IR luminescence (centered at around 1.54,,m) resulting from the 4I13/2,,,4I15/2 transition of the Er3+ ion, which contributes to the efficient energy transfer from the ligands to the Er3+ ion in both the Er(DBM)3phen complex and the ErDP gel (an antenna effect). The full width at half maximum (FWHM) centered at 1541,nm in the emission spectrum of the ErDP gel is 72,nm, which has potential for optical-amplification applications. Further theoretical analysis on the Er3+ ion in the ErDP gel shows that it appears to be a promising candidate for tunable lasers and planar optical amplifiers. [source]

Ultrafast laser written active devices

LASER & PHOTONICS REVIEWS, Issue 6 2009
M. Ams
Abstract Direct-write optical waveguide device fabrication is probably the most widely studied application of femtosecond laser micromachining in transparent dielectrics at the present time. Devices such as buried waveguides, power splitters, couplers, gratings, optical amplifiers and laser oscillators have all been demonstrated. This paper reviews the application of the femtosecond laser direct-write technique to the fabrication of active waveguide devices in bulk glass materials. [source]

A compact O-plus C-band switchable quad-wavelength fiber laser using arrayed waveguide grating

LASER PHYSICS LETTERS, Issue 8 2010
A.A. Latif
Abstract In this paper, a design of a quad-wavelength fiber laser (QWFL) operating in two different regions namely the O-band covering from 1302 nm to1317.4 nm and C-band from 1530.5 nm to 1548.0 nm is presented. Two different ASE sources from semiconductor optical amplifiers (SOAs) are used, one at 1310 nm and the other at1550 nm. By using a 1×24 channels arrayed waveguide grating (AWG) with 100 GHz interchannel spacing, the system is capable of generating 24 different wavelengths in more than 24 ways of quad-wavelength fiber laser with 0.6 nm and 0.8 nm of interval channel for O-band and C-band regions, respectively. (© 2010 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Photonic microwave bandpass filter with negative coefficients based on flat-top

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2010
Wang Jianping
Abstract In this article, a novel microwave photonic filter with negative coefficient using semiconductor optical amplifiers and Fiber Bragg Gratings is proposed. Three major factors, including input current, grating coefficients and the input signal power are analyzed and compared respectively with scrutinize their affects to the filter response. Through the simulation, a better performance of the flat-top microwave photonic filter can be achieved. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 9,13, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24824 [source]

Four-wave mixing characteristics in SOAs with optimum time-delays between pump and probe pulses

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2007
Narottam Kumar Das
Abstract We have analyzed the four-wave mixing (FWM) characteristics in semiconductor optical amplifiers (SOAs) with optimum time-delays between pump and probe pulses by the finite-difference beam propagation method. This study is very important to achieve the high FWM conversion efficiency and to clarify the timing jitter. From the simulations, we have clarified that the FWM conversion efficiency increases with optimum time-delays between pump and probe pulses in SOA for short optical pulses. In the experiment, we have found the similar tendency. Therefore, we have obtained an excellent agreement between the simulation and experimental results of high FWM conversion efficiency in SOAs with optimum time-delays between pulses. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1182,1185, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22389 [source]

Simulation and measurements of current-injected gain control in semiconductor optical amplifiers

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2004
Cristiano M. Gallep
Abstract A semiconductor optical amplifier simulator (SOASim), used to analyze in-line optical amplifiers, current-injected space switches, and electro-optical regenerators, is presented. The effects of amplitude-modulated injected current in the techniques of feed-forward gain control (FFGC) and pre-impulse-step injected current (PISIC) are included. Experimental results are in good agreement with simulations. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 477,481, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20177 [source]

Toward control of point defects in lithium fluoride thin layers

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2007
R. M. Montereali
Abstract Point defect formation and stabilization properties, as well as their peculiar spectroscopic characteristics, locally modify the optical properties of insulating materials. Thin layers containing high concentrations of colour centres, hosted in a LiF single crystal and/or a polycrystalline matrix, offer the opportunity to develop innovative light-emitting photonic devices. Control of all the critical parameters should be required on spatial dimension comparable with the optical wavelengths. Recent developments in laser technologies, electron and particles beam methods, and novel photon sources, have opened a wide range of opportunities. An overview of the most significant advances in this field is provided, with particular emphasis on colour-centre LiF-based innovative miniaturised light sources, optical amplifiers and lasers. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]