Development and applications of nonlinear optical spectroscopy: 15th ECONOS/35th ECW meeting in Gothenburg (Sweden)

Abstract

The joint conference of the European Conference on Nonlinear Optical Spectroscopy (ECONOS) and European CARS Workshop (ECW) covers all theoretical and experimental aspects of nonlinear optical spectroscopy and microscopy. Topics include Coherent anti-Stokes Raman scattering (CARS) spectroscopy and microscopy, and other forms of coherent Raman scattering, other approaches to the detection of nonlinear optical responses in time and frequency domain, and investigations of the physical and chemical processes defining the spectral signatures in different nonlinear media. Also, emerging analytical techniques and their applications in biomedical research, material science, and engineering are discussed. The 15th ECONOS conference and 35th CARS workshop were held in Gothenburg, Sweden, on 24–27 April 2016, chaired by David Sedarsky and Stina Hemdal (Chalmers University of Technology). Altogether, 50 participants shared their research in oral sessions and poster sessions and participated in lively discussions and social activities. After an invited lecture and a welcome reception in the historic Chalmerska Huset on Sunday, the regular scientific program began on Monday morning at the same place. Five invited talks were given during the course of the conference, followed by contributed oral presentations, and two poster sessions. This special section of the Journal of Raman Spectroscopy constitutes a selection of three papers presented at ECONOS/ECW 2016. Due to the broad scope of the conference, the papers cover a broad range of methods and their applications to a variety of systems. The special section starts with a contribution by Martinez et al. 1 who applied a pump-probe Raman-Raman technique to obtain high-resolution Raman spectra of vibrationally excited states in a series of acetylene isotopologues. They utilized the naturally occurring process of vibration-to-vibration collisional relaxation to populate excited states of interest. Some of these states were observed and studied for the very first time. Meißner et al. 2 carried out a feasibility study on the use of a Raman-active crystal in picosecond-CARS of nitrogen. The Raman crystal facilitated narrowband stimulated Raman scattering (SRS) to produce a coherent beam for three-color CARS thermometry. The concept was demonstrated by temperature measurements at ambient conditions and in a fuel-rich sooting ethylene/air flame. The third paper represents a theoretical study of hybrid fs/ps-CARS by Marrocco 3. Hybrid fs/ps-CARS is a time-domain and frequency-resolved method, where interaction of a Raman medium with simultaneous femtosecond (fs) pump and Stokes pulses is interrogated by means of a delayed picosecond (ps) probe. The resulting anti-Stokes signal is usually studied by means of numerical methods built on the conventional time-dependent model of Raman coherence. The paper presents analytical closed-form solutions to the time model and validates their reliability against published experimental results. The results show that the method allows a fast signal reconstruction and provides adequate spectral accuracy. This ECONOS/ECW special section highlights the continuous progress in the area of nonlinear optical spectroscopy and its applications across the science and engineering disciplines. The enthusiasm and creativity of the scientific community as well as the rapid development of novel and improved experimental equipment will ensure an exciting future of nonlinear spectroscopy research. We would like to thank all the delegates, presenters of talks and posters, helpers in the background, and sponsors, which made the 2016 ECONOS/ECW meeting in Sweden an enjoyable and memorable event. Special thanks to the Editor-in-Chief of the Journal of Raman Spectroscopy, Larry Nafie, for making this special section possible, and of course, to all the authors and reviewers of the papers for their invaluable contribution.