Coherent multidimensional spectroscopy (CMDS) encompasses a family of experimental strategies involving the nonlinear interaction between electric fields and a material under investigation. This approach has several unique capabilities: (1) resolving congested states, (2) extracting spectra that would otherwise be selection-rule disallowed, (3) resolving fully coherent dynamics, (4) measuring coupling, and (5) resolving ultrafast dynamics. CMDS can be collected in the frequency or the time domain, and each approach has advantages and disadvantages. Frequency domain ``Multi-resonant'' CMDS (MR-CMDS) requires pulsed ultrafast light sources with tunable output frequencies. These pulses are directed into a material under investigation. The pulses interact with the material, and due to the specific interference between the multiple fields the material is driven to emit a new pulse: the MR-CMDS signal. This signal may have a different frequency and/or direction than the input pulses, depending on the exact experiment being performed. The MR-CMDS experiment involves tracking the intensity of this output signal as a function of different properties of the excitation pulses. These properties include (1) frequency. (2) relative arrival time and separation (delay), (3) fluence, and (4) polarization, among others. Thus MR-CMDS can be thought of as a multidimensional experimental space, where experiments typically involve explorations in one to four of the properties above. Because MR-CMDS is a family of related-but-separate experiments, each of them a multidimensional space, there are special challenges that must be addressed when designing a general-purpose MR-CMDS instrument. These issues require development of software, hardware, and theory. Part I: Background introduces relevant literature which informs on this development work. Part II: Development presents five strategies used to improve MR-CMDS: (1) processing software, (2) acquisition software (3), active artifact correction, (4) automated OPA calibration, and (5) finite pulse accountancy. Finally, Part III: Applications presents four examples where these instruments, with these improvements, have been used to address chemical questions in semiconductor systems.

"Ultrafast coherent multi-dimensional spectroscopies are a powerful set of techniques used to unravel complex processes. These processes range from electronic coherences in molecular chromophores to many-body interactions in quantum-confined materials. Yet these spectroscopies remain challenging to implement at the high frequencies of vibrational and electronic transitions, thereby limiting their widespread use. The work herein demonstrates three significant methodological improvements of two-dimensional spectroscopy at optical frequencies, followed by applications of the method on two different systems. First, we introduce a hollow-fibre setup for the production of broadband visible pulses. This source is comparatively simple to operate, and yields stable, 45 [mu]J pulses over the 520-700 nm region. Second, we demonstrate the feasibility of two-dimensional electronic spectroscopy in a single beam. By appropriately modulating the phases of the pulses within the beam,we show that it is possible to directly read out the relevant optical signals. This work shows that one needs neither complex beam geometries nor complex detection schemes in order to measure 2D spectra at optical frequencies. Finally, we introducea setup for complete and independent polarization control of each pulse in the sequence. Together, these methodological improvements represent important enabling steps towards the longstanding goal of achieving an "Optical NMR", and extendsthe realm of all-optical multi-dimensional spectroscopies to spatially heterogeneous samples. The methods are applied on two classes of systems. The model system Nile Blue is used to validate the performance of the instrument. The spectrometeris then used to reveal new processes in colloidal semiconductor CdSe nanocrystals, a system of contemporary interest." --

The breadth of scientific and technological interests in the general topic of photochemistry is truly enormous and includes, for example, such diverse areas as microelectronics, atmospheric chemistry, organic synthesis, non-conventional photoimaging, photosynthesis, solar energy conversion, polymer technologies, and spectroscopy. This Specialist Periodical Report on Photochemistry aims to provide an annual review of photo-induced processes that have relevance to the above wide-ranging academic and commercial disciplines, and interests in chemistry, physics, biology and technology. In order to provide easy access to this vast and varied literature, each volume of Photochemistry comprises sections concerned with photophysical processes in condensed phases, organic aspects which are sub-divided by chromophore type, polymer photochemistry, and photochemical aspects of solar energy conversion. Volume 34 covers literature published from July 2001 to June 2002. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.

Fluorescence methods are being used increasingly in biochemical, medical, and chemical research. This is because of the inherent sensitivity of this technique. and the favorable time scale of the phenomenon of fluorescence. 8 Fluorescence emission occurs about 10- sec (10 nsec) after light absorp tion. During this period of time a wide range of molecular processes can occur, and these can effect the spectral characteristics of the fluorescent compound. This combination of sensitivity and a favorable time scale allows fluorescence methods to be generally useful for studies of proteins and membranes and their interactions with other macromolecules. This book describes the fundamental aspects of fluorescence. and the biochemical applications of this methodology. Each chapter starts with the -theoreticalbasis of each phenomenon of fluorescence, followed by examples which illustrate the use of the phenomenon in the study of biochemical problems. The book contains numerous figures. It is felt that such graphical presentations contribute to pleasurable reading and increased understand ing. Separate chapters are devoted to fluorescence polarization, lifetimes, quenching, energy transfer, solvent effects, and excited state reactions. To enhance the usefulness of this work as a textbook, problems are included which illustrate the concepts described in each chapter. Furthermore, a separate chapter is devoted to the instrumentation used in fluorescence spectroscopy. This chapter will be especially valuable for those perform ing or contemplating fluorescence measurements. Such measurements are easily compromised by failure to consider a number of simple principles.

This volume reviews the latest trends in organic optoelectronic materials. Each comprehensive chapter allows graduate students and newcomers to the field to grasp the basics, whilst also ensuring that they have the most up-to-date overview of the latest research. Topics include: organic conductors and semiconductors; conducting polymers and conjugated polymer semiconductors, as well as their applications in organic field-effect-transistors; organic light-emitting diodes; and organic photovoltaics and transparent conducting electrodes. The molecular structures, synthesis methods, physicochemical and optoelectronic properties of the organic optoelectronic materials are also introduced and described in detail. The authors also elucidate the structures and working mechanisms of organic optoelectronic devices and outline fundamental scientific problems and future research directions. This volume is invaluable to all those interested in organic optoelectronic materials.

The topics range from single molecule experiments in quantum optics and solid-state physics to analogous investigations in physical chemistry and biophysics.