Near-Field Scanning Optical Microscope Combined with Digital Holography for Three-Dimensional Electromagnetic Field Reconstruction

International audienceNear-field scanning optical microscopy (NSOM) has proven to be a very powerful imaging technique that allows overcoming the diffraction limit and obtaining information on a scale much smaller than what can be achieved by classical optical imaging techniques. This is achieved using nanosized probes that are placed in close proximity to the sample surface, and thus allow the detection of evanescent waves that contain important information about the properties of the sample on a subwavelength scale. In particular, some aperture-based probes use a nanometer-sized hole to locally illuminate the sample. The far-field radiation of such probes is essential to their imaging properties, but cannot be easily estimated since it highly depends on the environment with which it interacts. In this chapter, we tackle this problem by introducing a microscopy method based on full-field off-axis digital holography that allows us to study in details the three-dimensional electromagnetic field scattered by a NSOM probe in different environments. We start by describing the NSOM and holography techniques independently, and continue by highlighting the advantage of combining both methods. We present a comparative study of the reconstructed light from a NSOM tip located in free space or coupled to transparent and plasmonic media. While far-field methods, such as back focal plane imaging, can be used to infer the directionality of angular radiation patterns, the advantage of our technique is that a single hologram contains information on both the amplitude and phase of the scattered light, allowing to reverse numerically the propagation of the electromagnetic field towards the source. We also present Finite Difference Time Domain (FDTD) simulations to model the radiation of the NSOM tip as a superposition of a magnetic and an electric dipole. We finally propose some promising applications that could be performed with this combined NSOM-holography technique

It’s not what you say, it’s the way you say it! Effective message styles for promoting innovative new services

While innovations are critical to firms' long-term survival, they have a high failure rate. Identifying the factors that encourage consumer adoption of innovations is therefore essential for the successful management of new products and services. While prior research suggests that two message styles (i.e., metaphors and narratives) can help convey the benefits of new services, extant scholarly work has not examined which style increases adoption intentions to a greater extent. Study 1 demonstrates that metaphors enhance adoption intentions more than narratives for incrementally new services (INSs) but not for really new services (RNSs). Study 2 shows that low-figurativeness metaphors enhance adoption intentions more than high-figurativeness metaphors for INSs but not for RNSs and that consumers' negative cognitive responses underlie this effect. These findings have important implications for theory and practice

Exploring neural cell dynamics with digital holographic microscopy.

In this review, we summarize how the new concept of digital optics applied to the field of holographic microscopy has allowed the development of a reliable and flexible digital holographic quantitative phase microscopy (DH-QPM) technique at the nanoscale particularly suitable for cell imaging. Particular emphasis is placed on the original biological information provided by the quantitative phase signal. We present the most relevant DH-QPM applications in the field of cell biology, including automated cell counts, recognition, classification, three-dimensional tracking, discrimination between physiological and pathophysiological states, and the study of cell membrane fluctuations at the nanoscale. In the last part, original results show how DH-QPM can address two important issues in the field of neurobiology, namely, multiple-site optical recording of neuronal activity and noninvasive visualization of dendritic spine dynamics resulting from a full digital holographic microscopy tomographic approach

Does advertising appeal type make a difference? A new sustainable fashion product by a luxury and mainstream brand

Sustainability is not only at the forefront of the mainstream brands\u2018 agenda. Many luxury brands already engage in sustainability actions, either launching sustainable versions of their products or develop \u201cresponsible luxury\u201d strategies and policies. This chapter explores two types of advertising appeals for sustainable new products communications: those that deliver consumer benefit (i.e. self-benefit) and those that deliver societal benefit (i.e. others-benefit). Furthermore, this research investigates whether the advertising appeal types moderate the effect of brand types, namely mainstream versus luxury, on consumers\u2019 reactions toward new sustainable products. The results of the experiment indicate that consumers\u2019 purchase intention increases when a new sustainable product is produced by a mainstream brand rather than a luxury one when advertising communicates self-benefits. When the message is focused on \u201cothers-benefit\u201d instead of \u201cself-benefit\u201d, consumers\u2019 attitude toward a new sustainable product increases for a luxury brand. On the other hand, consumers\u2019 attitude toward a new sustainable product decreases when the message is \u201cothers-benefit\u201d for a mainstream brand