Principal component analysis of UV-VIS-NIR transmission spectra of matured wine distillates (1-40 years aged) produced
by three Moldavian manufacturers allows to characterize with sufficient certainty the eleven chemical parameters of
considered alcoholic beverages: contents of acetaldehyde, ethyl acetate, furfural, vanillin, syringic aldehyde and acid, etc.
Numerical simulation of broadband fiber Raman amplifiers with multiple pumps is carried out. Rayleigh scattering, amplified
spontaneous emission and signal-to-signal, pump-to-pump and signal-to-pump conversions are taken into account.
Special emphasis is placed on the noise performance of the amplifiers. Calculation of ultimate spectral efficiency
of information transmission and capacity of fiber Raman amplifiers is fulfilled.
KEYWORDS: Optical amplifiers, Glasses, Fiber amplifiers, Amplifiers, Telecommunications, Silicates, L band, Absorption, Signal to noise ratio, Systems modeling
Information capacity for unsaturated gain regime is proposed as new figure of merit for host glasses for Er-doped fiber
amplifiers that are considered as components of optical communication systems. Silicate and phosphate glasses are
proved to have the highest total information capacity over the S-, C- and L-bands. In wideband communication systems
tellurite glasses are shown to have the maximum capacity.
Pump conditions optimization is performed for erbium-doped fiber amplifier with dual wavelength bidirectional quasi-two-
level pumping to obtain low noise figure, high efficiency of pump power conversion and sufficiently wide and flat
gain spectrum in L-band.
The modeling of erbium-doped fiber amplifier with three-level forward pumping and quasi-two-level backward pumping
has been performed. The optimal pumping conditions for achievement of the flattest gain spectrum have been found by
means of genetic algorithm.
Pump conditions optimization has been performed for one-stage EDFA with three-level forward pumping and quasi-twolevel
backward pumping. The optimization allows to achieve low noise figure, high efficiency of pump power conversion
and sufficiently wide and flat gain spectrum.
KEYWORDS: Optical amplifiers, Fiber amplifiers, Systems modeling, Amplifiers, Telecommunications, Absorption, S band, Signal to noise ratio, Ions, Interference (communication)
Ultimate spectral efficiency of information transmission of erbium-doped fiber amplifiers and lumped amplifier chains is considered on the basis of the number-state model for linear communication channel. For single amplifier the efficiency is about 12-14 bit⋅s-1Hz-1 at 1 μW⋅GHz-1 input signal power density depending on pumping conditions. For long-haul communication lines it approximates 7-14 bit⋅s-1 Hz-1 for spectral density of input signal power of 1-100 μW⋅GHz-1.
New type of gain flattening filter for WDM systems is considered. It is based on the use of nonlinear Fabry-Perot interferometer as an amplitude mask in the Fourier-synthesis of short optical pulses. Results of numerical simulation show that the flat broadband gain spectrum of EDFA can be obtained in the proposed scheme by means of applying additional holding beams of mW powers.
Several types of switches based on optically bistable (OB) thin Fabry-Perot interferometers are reviewed. Applications for time-division multiplexing are proposed and demonstrated experimentally using both separate OB pixels and those coupled by transverse effects in arrays of various types. Compatibility with modern WDM/DWDM fiber optical networks is discussed.
New type of gain equalization filter for WDM systems is proposed. It is based on the employment of nonlinear Fabry-Perot interferometer as a pump controlled mask in the layout of Fourier-synthesis of short optical pulses. Results of numerical simulation show that the flat gain spectrum of EDFA can be achieved over the whole C-band in the equalization scheme proposed at moderate pumping power and small additional losses.
Application of wavelets is investigated with ultimate time-frequency resolution for laser communications. The optimum encoding method for reaching the maximum rate of information transmission is shown to be based on WAVE-wavelets.
Technical parameters and main experimental features of laser complex for investigation of bistable phenomena in GaAs/GaAlAs interferometers and for modeling basic digital devices for optical signal processing (logical elements, switching devices, etc.) are reported.
All-optical data shift operation in a planar array based on transverse effects in optical bistability in an all-epitaxial GaAs/GaAlAs Fabry-Perot interferometer is reported. Transfer of information bit along a shift register takes about 6 ns.
Information-rate densities in optical communication systems are investigated on the base of the number-state model. Results of numerical simulation show that the considered characteristics increase monotonically with increasing signal power, reducing passband width and environment temperature. For quasi-monochromatic optical communication channels quantum-statistical peculiarities of information carriers can not be taken into account at large enough singal powers when fluctuation noise can be neglected.
The maximum achievable characteristics of optical communication systems with different kinds of pulse position modulation have been investigated within the framework of the number-state model. It is shown that the ultimate efficiency in optical systems with ordinary pulse position modulation is determined by the ratio of the number of photons in the signal chip to the number of chips in the signal frame. Maximum achievable efficiencies of all considered methods is compared also. The companions shows that at great values of modulation format the ultimate efficiency of pulse position modulation is higher than that of the multipulse modulation. Overlapping pulse position modulation is shown to be the most favorable one for communication channels. The application of additional encoding to such systems allows to achieve the highest power efficiency of information transmission in optical communication channels.
Dynamics of switching waves in optically bistable all- epitaxial GaAs/GaAlAs Fabry-Perot interferometers is studied experimentally. Realization of planar optical shift register based on propagation of switching waves between neighbor pixels in the plane of bistable layer is proposed.
Principles of formation and controlled propagation of switching autowaves in optically bistable interference structures are considered. On this basis methods and devices are developed for read-in, storing, read-out, switching and transfer of information light signal sin the plane of 2D- arrays of nonlinear optical elements of micron size. A peculiarity of these methods is the possibility of shift data laterally in the array's plane in a direction that is perpendicular to the direction of incident light beams without its interim transformation into electrical signals. This distinctive feature enables developing new architecture concepts of optical information processing systems. Examples of numerical simulations and experimental realizations are presented of optical digital devices with a wide range of functional applications such as Boolean logic elements, shift registers, multiplexers/demultiplexers, basic planar ring processors, etc. The limiting operation parameters of the above devices are discussed.
We investigate some limiting characteristics of two- component optoelectronic system for information transmission on the base of number-state model and Brillouin's negentropy principle. The expression for the upper bound of the capacity of considered communication system is obtained. It is shown, that the capacity of the whole system is substantially limited by the speed characteristics of an optical subsystem. Only in the limited power range of optical signal it is determined by speed of the information transmission in an electronic subsystem. Such a consideration enables us to get deeper insight into the basic principles of information processing in channels with different nature of carriers.
The high-rate characteristics of two models of photonic communications channels are investigated in the case of negligible thermal noise of the receiver. It is shown that with use of m-ary amplitude coding (m > 2) the rate of the fault-free transmission of information can be just several times less than the fundamental restrictions, imposed by quantum-statistical properties of information carriers.
KEYWORDS: Quantum communications, Quantum information, Probability theory, Interference (communication), Fermions, Telecommunications, Channel projecting optics, Information technology, Data transmission, Information theory
On the base of entropy defect principle the models are considered of narrow-band quantum communication channels and compared with the classic description of information channels. The classic model is shown to be applicable in a wide range of channels' parameters. But in the case of fermionic channels it is necessary to take into account that values of signal power and channel capacity are limited. These maximum values can be approximated by the simple expressions. Bosonic channels are free of these limitations. The rough quantum model of narrow-band bosonic channels gives too high values of capacity at low communication rate as compared with accurate one.
On the base of entropy defect principle the model of ideal opto-electronic converter is considered. Main restriction on information transmission in opto-electronic communication networks is shown to be caused by the data conversion process from optical part of the net to electronic one. Though, in principle, under certain conditions some amount of energy necessary for data conversion from optical communication channel to electronic one can further be recovered.
KEYWORDS: Interference (communication), Quantum information, Data transmission, Numerical simulations, Photons, Electrons, Receivers, Channel projecting optics, Information technology, Information theory
Hence photons and electrons obey different statistics, information features of noisy photonic and electronic channels are essentially different in quantum limit. For one dimensional channels quantum effects start to influence the information capacity when the signal power is comparable with the equilibrium noise power in a channel. Finite frequency band fermionic channels are limited in respect to the information rate growth. Bosonic channels are free of this limitation.
A Nd:YAG Laser IntraCavity SpectroDetector (Nd:YAG LICSD) is described for sensoring small methane (CH4) concentration in the atmosphere. The concentration detectability of the Nd:YAG LICSD of about 0.003 is experimentally demonstrated and of about 1 ppm is discussed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.