The nano-textured surface of black silicon can be used as a surface-enhanced Raman scattering (SERS) substrate. Sputtered gold films showed increasing SERS sensitivity for thicknesses from 10 up to 300 nm, with sensitivity growing nonlinearly from around 50 nm until saturation at 500 nm. At 50 nm, a cross over from a discontinuous to a fully percolated film occurs as revealed by morphological and electrical measurements. The roughness of the Au coating increases due to formation of nanocrystallites of gold. Structural characterization of the black-Si needles and their surfaces revealed presence of silicon oxide and fluoride. The sharpest nano-needles had a tip curvature radius of similar to 10 nm. SERS recognition of analyte using molecular imprinted gels with tetracycline molecules of two different kinds is demonstrated.

We present a set of practical rules critical for designing and building a modern nanotechnology laboratory, focused on photonic applications in a cleanroom environment. We show the impacts on time, cost and quality of early design decisions and its importance on achieving the final fully functional laboratory. Best practice examples are presented for setting up a modern laboratory/facility, following analysis of the time, cost and quality constraints. The case study presented is the engineering and architectural solution of the nanofabrication cleanroom facility in the Advanced Technology Centre at Swinburne University of Technology, Australia. Set of practical rules is established for the cost and time efficient set up of the nanotechnology facilities for the research and development.

Stimulation emission depletion provides a principle for superresolution microscopy imaging by using two laser beams [1]. One laser beam is responsible for switching on a physical or chemical process and the other one for switching-off. Appling this principle into direct laser writing can lead to superresolution fabrication methods. Here we report on superresolution photoinduction-inhibited nanolithography (SPIN), in which case, one laser beam acts for photoinduction and the other for inhibition. A particular example of photoinduction is photopolymerisation, which is a major method in direct laser writing [2, 3]. We show that the physical mechanism of this kind of SPIN can be well explained by the kinetic coupling (KIC) model and that the smallest feature size of the polymerised dots we have achieved is approximately 40 nm, which is λ/12 (Fig. 1). The integration of SPIN with two-photon excitation potentially provides a capability for three-dimensional SPIN. Our result forms a platform for nanophotonic fabrication of optical chips [3], high-density optical data storage [4] and nano-surgery if a flexible compact optical microscope is adopted [5].

As discussed in Chapters 1 and 2, biological tissue is a highly scattering medium which will affect image resolution, contrast and signal level. This chapter discusses the effect of multiple scattering in a tissue-like turbid medium on two-photon fluorescence microscopy. Section 3.1 discusses a model based on imaging of microspheres embedded in a turbid medium. A quantitative study of the limiting factors on image quality is given in Section 3.2. In particular, the limitation on the penetration depth in turbid media, revealed from Monte-Carlo simulation and experimental measurements, is presented in Section 3.3.

In this chapter, we introduce a new trapping and excitation technique, which utilises a single femtosecond pulse infrared illumination source to simultaneously trap and excite a microsphere probe. The induction of morphology dependent resonance (MDR) in the trapped probe is achieved under two-photon excitation. Monitoring of the MDR in the trapped probe provides a contrast mechanism for imaging and sensing. The experimental measurement of MDR within a laser trapped microsphere excited under two-photon absorption is confirmed in Section 7.2. The effect of the laser power as well as the pulse width on the transverse trapping force is investigated in Section 7.3. The dependence of two-photon induced MDR on the scanning velocity of a trapped particle is then experimentally determined. These parameters are fundamental to the acquisition of images and sensing with femtosecond laser tweezers as described in Section 7.4.

As discussed in Chapter 6, the trapping volume of a far-field laser trapping geometry is approximately three times larger in the axial direction than that in the transverse direction. Such trapping volume elongation leads to a significant background and poses difficulties in the observations of nano-particle dynamics. In this chapter, we deal with near-field optics using focused evanescent illumination. The recent development of near-field optical tweezers is reviewed in Section 8.1. Section 8.2 introduces the new concept of near-field laser tweezing with a focused evanescent field. This technology is characterised both experimentally and theoretically in Section 8.3. Section 8.4 presents the utilisation of a femtosecond laser beam in a near-field optical trap. Finally, some discussions on this new method are given in Section 8.5.

Here we present a multifunctional algorithm. Firstly a super‐resolution method is presented for optically imaging the spatial distribution of semiconductor nanocrystals with nanometre localisation. Secondly highly resolved multiple photoluminescence trajectories of hundreds of single semiconductor nanocrystals are obtained simultaneously. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

We report on the use of a radially polarized beam for photothermal therapy of cancer cells labeled with gold nanorods. Due to a three-dimensionally distributed electromagnetic field in the focal volume, the radially polarized beam is proven to be a highly efficient laser mode to excite gold nanorods randomly oriented in cancer cells. As a result, the energy fluence for effective cancer cell damage is reduced to one fifth of that required for a linearly polarized beam, which is only 9.3% of the medical safety level.

1 Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences (FEIS) Swinburne University of Technology, H38, John Street, PO Box 218, Hawthorn, VIC, 3122, Australia 2 WiOptix, Inc., 101 SE 2 nd Place, Downtown Technology Centre, Gainesville, FL 32601, America 3 Department of Electrical and Computer Engineering, PO Box 116200, University of Florida, Gainesville, FL 32611-6200, America Email: hkang@groupwise.swin.edu.au

The introduction of femtosecond pulse lasers has provided numerous new methods for non-destructive diagnostic analysis of biological samples. This book is the first to provide a focused and systematic treatment of femtosecond biophotonic methods. Each chapter combines theory, practice and applications, walking the reader through imaging, manipulation and fabrication techniques. Beginning with an explanation of nonlinear and multiphoton microscopy, subsequent chapters address the techniques for optical trapping and the development of laser tweezers. In a conclusion that brings together the various topics of the book, the authors discuss the growing field of femtosecond micro-engineering. The wide range of applications for femtosecond biophotonics means this book will appeal to researchers and practitioners in the fields of biomedical engineering, biophysics, life sciences and medicine.