According to author's Chinese invented patent ZL96 I II 979.9 named "The method of separating image of AF/PSTM (atom force and photon scanning tunneling microscope)", the first system ofAF/PSTM has been developed. Its principle, photograph, block diagram and some images ofan examination sample have been given in this paper. There are three advantages of this system: (1) AF/PSTM can eliminate the optical false image which caused by topography of sample in PSTM; (2) The optical images and topographic image of sample are separated with this AF/PSTM; (3) From once scanning imaging two optical images (refractive index image and transmissivity image) and two AFM images (topography image and phase or grads oftopography image) can be obtained.

A novel optical imaging method that makes use of surface plasmon microscopy (SPM) and phase shift interferometry is developed. It is named phase shift interferometry-surface plasmon microscopy (PSI-SPM). In comparison with SPM, it can measure not only the intensity of the light reflected under SPR conditions, but also the phase of the light. The images of higher resolution (compared with SPM) can be obtained through the synthesis of the phase (color) and intensity (brightness) information.

A non-optical shear-force detection method to control the probe-simple distance for a scanning near field optical microscope (SNOM) is proposed. A rectangular piezoelectric bimorph beam is designed so that one piezo layer of the beam is used for vibrating the scanning probe and the other for detecting the vibration. Optical fiber probe is attached on one side ofthe beam to detect the shear force. When the beam is excited at resonance by the stimulation piezo layer, the other detecting layer can generate a maximum piezo voltage. The amplitude ofthe piezo voltage will decrease as the fiber tip gets close to the sample because ofthe shear force interaction experienced by the tip. The oscillating amplitude change, picked up from the detecting piezo layer, severe as feedback and shear force imaging signal. Shear force topographic and optical images of mother disc of compact disk and multicomponent compounds (Rb0 5Cs0.5Ag4I5) thin films have been taken. The results show that the improved system is easy-to-use and fit for study ofvarioi.is thin films.

Our research group has recently developed a new type scanning probe microscope —AF/ PSTM. Using this setup, the optical false image caused by the inclination of sample surface can be eliminated; the optical image and the topography image are separated; and also two optical images (refractive index image, transmittivity image) and two AFM images (topography image, phase image) are obtained during one scanning. As a primary biologic application, this setup is engaged in the imaging of some biologic samples. The primary images ofthese biologic samples are obtained. Due to the advantage of AFIPSTM, four images can be acquired at the same time during one scanning. Consequently more information ofsample is given by comparing these images. This work shows that the AF/PSTM may be improved to be a useful tool in biology research.

Scanning near-field optical microscope (SNOM) is a new photoelectrical tool for the research down to nanomcter scale. Recently, Gorecki et al. have proposed a promising archltectLlre ofmonolithic integrated miniature SNOM sensors composed of only three elements (a PIN detector, a VCSEL and a microtip) and have developed a wet etching method of fabricating GaAs microtips. However, the etching process can hardly be controlled precisely. In this report, we propose an improved technique for manufacturing Al0.3Ga0.7As microtips grown by self-assembled liquid-phase epitaxy (LPE) for integrated SNOM sensors. In conventional LPE growing process, we used the properties that AIGaAs surface can be easily partialy oxided and can spontaneously create micrometer-sized windows to grow pyramid-like microtips in the windows self-organizedly. Using this technique, the miniature pyramid-like probes can be directly grown onto the external facet of the VCSEL.

Using the Luttinger formulations, we have analyzed the propagation characteristics of an ultrashort (femtosecond) coherent radiation pulse in the transverse plane of a direct gap semiconductor quantum well waveguide structure (QWWS). The semiconductor QWWS is considered to possess degenerate valence subbands near the centre of the Brillouin zone. The photoinduced resonant transitions below the band edge to both 1s and 2s excitonic states from the light hole (lh) and heavy hole (hh) subbands have been considered. The cross-over between the lh and hh bands occurs in case of transverse plane where the light holes are found to play more dominant role than the heavy holes. We have analyzed the transient pulse propagation characteristics like pulse break-up and optical nutation. The transverse electric mode propagation is also studied in the QWWS assuming the same to behave as a three-layer asymmetric planar waveguide. Numerical analysis made for GaAs/AlGaAs QWWS duly shined by a 150 fs Ti:Sapphire laser shows good qualitative agreement of the present results with those available in literature.

Photopolymerizable materials are capable of recording high-efficiency volume holograms by changing the refractivity of the layer, for fringe spacing between 0.2 and 10 ?m. As the photosensitive emulsion is embedded between two glass plates, it is possible to open the sandwich after the recording and to analyze the free polymer surface using pulsed force mode of an atomic force microscope. The modulation of properties between the bright and dark fringes, photoinduced by an interference pattern are analyzed in terms of : - relief amplitude (the surface corrugation appearing after opening is due to the relaxation in surface of the constraints stored during the grating formation) ; - local variations of the mechanical polymer properties (they are related to the coupling of the spatially controlled photopolymerization with mass diffusion processes, giving rise to the microstructuration, e.g. regions with various segment densities). Taking into account all these data, improvement of the material is possible in view of applications in data storage or creation of optical diffractive elements. In particular, in the case of multiplexed gratings, it provides a means for visualizing the Young’s modulus pattern associated with each individual record and, therefore, optimizing the recording procedure.

In this paper, Lichtennecher method and module system simulation method were synthesized to present a formula giving the relation between the effective refractive index and pore-ratio of the polymer nanoporous film made of PS(polystyrene) PMMA(polymethyl-methacylate) and nano-pore. It can be used to design a nanoporous polymer film whose effective refractive index can be fine-tuned with great precision, which is of great importance and pratical value for the design and manufacture of the high performance nanoporous polymer optical waveguide whose effective refractive index difference between the core and the cladding is perfectly controlled and adjusted.

Nanometric light source is one ofthe most important elements in near-field optical system. In this paper the nearfield distribution of nano-aperture lasers (NAL) with square and asymmetrical C aperture are characterized by the method of 3D finite-difference time-domain (FDTD). The simulation results theoretically reveal that the output power peak from the asymmetrical NAL is three or four orders of magnitude higher than that from the normal square or round aperture with the comparable light spot size in the near-field region and power throughput is more than unity. The maximum ofthe field enhancement occurs at the C aperture size corresponding to one third ofwavelength. The effects of configuration, aperture dimension, electric field component, polarization and separation in local near field close to the aperture have been investigated theoretically and numerically. The mechanism of electromagnetic field enhancement is also discussed. The asymmetrical NAL with higher throughput may expand the range of applications possible in near-field optics.

Vertically stacked QD growth in precision can be incorporated to develop new structures and improve the size and spatial distribution ofthe strain-induced QD ensemble. Photoluminescence (PL) ofquantum dots embedded in high potential barriers is studied as functions ofbarrier thickness, temperature, and laser excitation power. With the increase of un-doped barrier thickness, both of strengthened two-dimensional electron gas (2DEG) structure and strongly localized electron wave functions can increase the carrier recombination. The optical properties of different-barrier-thickness samples exhibit different characteristics with the decreased measurement temperatures. The PL recombination characteristic of the samples with the barriers adjacent to a Si-doping GaAs layer is different from that of samples with barrier adjacent to an i-GaAs layer.

Using optical tweezers we have developed a biomechanical detection system for single molecules detection. This system can control the sample bead which is used as the handle of single molecules with nanometer precision, it also can make quantitative measurements of displacement with nanometer resolution, and measure the Pico-Newton force involved in the dynamical process of the movement of a single biomolecule. We combined two Donut-Mode optical traps with two high-precision observation setups in this system. Experiments described in this paper demonstrate the performance of the system. In our experiments, we monitored the Brownian motion ofpolystyrene beads; as a result we can calculate the optical-trap stiffness. In summary, the system can be used in the research of the dynamical motion of a single biomolecule.

We report the waveguiding properties of photonic crystal fibers by adapting the effective index method. It has been shown that the waveguiding characteristics can be engineered for different configurations of PCFs. It is shown that the zero dispersion point can be shifted below 1.27?m. Nearly zero dispersion-flattened behavior is observed for a specific combination of cladding parameters of photonic crystal fiber.

We present experimental results of time-resolved signals of photoconductive (PC) switches with an ultrafast scanning tunneling microscope, which combines ultrashort laser techniques with scanning tunneling microscope (STM) to obtain simultaneous high temporal and spatial resolution. The picosecond electrical transients were generated by optically exciting the photoconductive switch between a high-speed coplanar strip transmission lines. The measured PC switch demonstrated a linear relation between the amplitudes of the time-resolved pulse signals and the photoconductive currents as well as a linear relation between the amplitudes ofthe signals and the bias voltage applied to the PC switch. The resolved transient signal in contact mode showed a FWHM of 3.2 ps, and the transient signals in non-contact mode were from the capacitive coupling between the tip and the coplanar transmission line.

In a traditional sense, Dammann grating can transfer the beam into one dimensional spots or two dimensional spots, which can be used for beam splitter or array illuminators. This paper presents a new kind Dammann grating that can realize the equal peak value intensity circular diffractive field. We call it circular Dammann grating. And the order of the grating is the number of the circular diffractive spectrums. We use the binary phase-only mask in our numerical simulation, we have obtained the optimized parameters, including the circular phase and radius of each ring. Our optimization algorithm is the simulated annealling algorithm. Different order circular Dammann grating can generate different circular diffractive field. We have calculated the number from 1 to 9 diffractive spectrums and found that with the increase of the encoding number of circular Danimann grating, more circular equal-intensity diffractive spectrums can be realized. Different order Dammann gratings have practical applications for different purposes. For example, the first order circular Dammann grating produce the smooth intensity in the central lobe, which can be used as the flat-top intensity for the wide applications of optical interference, such as producing optical fiber grating, optical detection, etc. The multi order Dammann grating can be used for beaming shaping and laser demonstration. In conclusion, circular Dammann grating is a novel diffractive optical element that has wide applications in optical information system.

We demonstrate a novel technique to fabricate a gelatin film containing Au-nano-particles. The technique is based on silver halide photographic development. We investigated third-order non-linearity of the film by forward-four-wave-mixing technique. Peak absorption appeared at the wavelength of 560nm. Self-diffraction by the use of third order nonlinear grating formed by intense pico-second pulses was observed. Experimental diffraction efficiency was proportional to the square of the pump intensity. Third-order susceptibility ?(3) of the film was estimated to be 1.8 10-7esu.

In real photonic band gap (PBG) materials, the PBG is highly anisotropic. In this paper, we propose an optical memory composed of a three-level atom embedded in the realistic anisotropic PBG structures without external driving lasers, which can be considered as essential components for a novel class of computation including an optical quantum computation.

Surface plasmon excitations with different nanostructure modulations on the interface between metal and dielectric were interesting to investigate. The study was performed by measuring optical transmission through perforated metallic thin film. Experimental observations on dependences of periods, depths, and widths of nanostructures on the transmission of gold film were reported. Furthermore, simulations by finite difference time domain (FDTD) method were used to predict the variations of transmission and reflection with periods.

Construction of a tapping-mode tuning fork with a short fiber probe as the force sensing element for near-field scanning optical microscopy is reported. This type of near-field scanning optical microscopy provides stable and high Q factor at the tapping frequency of the tuning fork, and thus gives high quality NSOM and AFM images of samples.We present results obtained by using the short tip tapping-mode tuning fork near-field scanning optical microscopy measurements performed on a single mode telecommunication optical fiber and a silica based buried channel waveguide.

The technique ofoptical fiber trapping has been successfully used to manipulate small particles, while near field optical tweezers based on the sub-wavelength size fiber tip has been proposed to trap nanometric particles. With some similar physical mechanism and properties they are investigated and analyzed respectively in this paper. Firstly the optical field distributions of uncoated fiber probe with different radii of tip, from several microns down to zero, are calculated and analyzed by 3D finite-difference time-domain (FDTD) method. Then the metal-coated fiber probe is also discussed in the same way. In conclusion, the light from the fiber probe with the radius larger than wavelength is converged at a cometic spot, whatever with or without metal coating. When the radius of metal-coated tip is smaller than halfofwavelength, the evanescent field occurs and decays rapidly. The local field enhancement dominates in the metal-coated probe ifthe radius is smaller.

Nanocrystalline CeO2 of different sizes were prepared by calcining CeO2modify with oleic acid at different calcination temperatures, TEM analysis indicated that nanocrystalline CeO2 was spherical in shape.The average sizes and relative density of nanocrystalline CeO2 increased with the increas ofcalcination temperature .XRD patterns showed that the synthesized CeO2 was cLibic system and space group was O5H?FM 3M when calcination temperature was in the range of450-900°C.

This paper describes the Raman mapping spectrum studies on polycrystalline silicon thin films which were cultivated on glass plate by the way of PECVD. The characteristic peak (520cm-1) of nano-polycrystalline silicon it can shift to the longer wavelength under effect of compression stress so the effect of stress can mask the effect of nano-effect. We studied the cracks on the surface of polycrystalline silicon thin films caused by stress with Raman mapping spectrum and we find the Raman peak of polycrystalline silicon moved to 518 cm-1 in the middle of crack, in which the stress had been released. We obtained the stress distribution image by mapping the position of the peak 518 cm-1 and we got the same image by mapping the peak width of the peak 518 cm1 we studied the transition peak 510 cm-1 between 520 cm-1 and 480 cm-1 by curve fitting and we find the position and width of this peak are very sensitive to stress. Furthermore, the amorphous peak 480 cm-1 is not as sensitive as peak 520cm-1 to stress. So it is difficult to get an accurate stress distribution image by mapping the amorphous peak.

Nonlinear optical transimittance in the Super-RENS (super-resolution near-field structure) [glass/SiN(20nm)/ Sb(15nm) /SiN(20nm)] was investigated using a static transmittance measuring system with a focused laser illumination. The result shows an optical switching property with a strong nonlinear effect. Some SEM(Sanning Electron Microscope) images ofrecording spots in a PC(Phase Change) GeSbTe layer with and without the Super-RENS layers covering on it are presented. The images demonstrate the field enhancement effect due to the Super-RENS layers. The cause of the enhancement is considered as the local plasmon excitation.

Based on the exact solutions of Maxwell’s equations, we have studied the basic theoretical properties of submicron and nano-diameter air-cladding silica-wire waveguides. The single-mode condition and the modal field of the fundamental modes have been obtained. Silica wires with diameters of 100-1000nm and lengths ranging from hundreds of micrometer to over 1 millimeter have been fabricated. SEM examination shows that these wires have uniform diameters and smooth surfaces, which are favorable for optical wave guiding. Light has been sent into these wires by optical coupling, and guiding light through a bent wire has also been demonstrated. These wires are promising for assembling photonic devices on a micron or submicron scale.