[en] The quality of reconstructed impulse response of holograms displayed on a three DMD modulators of different models was experimentally evaluated. The integral parameter of modulators' optical quality - the size of sufficiently flat area of matrix surface - was estimated according to the developed technique. The results of holograms reconstruction are analyzed. (paper)

[en] Spatial variations of plasma parameters were measured in a large, inductively coupled plasma (ICP) chamber (diameter: 610 mm) by using a fast scanning probe (FSP), which could scan a length of 100 cm at a speed of 0.8 m/sec. The plasma parameters were measured by using single, triple, and emissive probes installed at the tip of FSP. A new modified diffusion model was introduced to analyze the spatial variations of the normalized density since the variable mobility model cannot explain the current measured data. Inclusion of ion thermal motion gives more reasonable results than the variable mobility model

[en] An experimental focusing of the extended images of the linear objects inclined at the angle 45 deg with respect to the optical axis of the system is described. For this purpose a new optical element, an image orthogonalizator, has been used. The structure of the two-dimensional field of signals generated in the focal plane of the cylindrical lens is analyzed

No abstract available

[en] An endoscope-compatible, submicrometer-resolution scanning confocal microscopy imaging system is presented. This approach, spectrally encoded confocal microscopy (SECM), uses a quasi-monochromatic light source and a transmission diffraction grating to detect the reflectivity simultaneously at multiple points along a transverse line within the sample. Since this method does not require fast spatial scanning within the probe, the equipment can be miniaturized and incorporated into a catheter or endoscope. Confocal images of an electron microscope grid were acquired with SECM to demonstrate the feasibility of this technique. copyright 1998 Optical Society of America

[en] We propose a method for laser pulse temporal shaping applying just an opaque solid 2D mask as a shaping element. The research is motivated by recent experimental data on temporal distortions produced in chirped picosecond pulses by spatial light modulators (SLMs) commonly used in shaping schemes and consequent demand for alternative solutions.

In the presented scheme, the effect of grey-level masking in the spectral domain is achieved by dimensional reduction from 2D shaping on air to 1D obtained modulation at the fiber output. The mask is placed in the Fourier plane of a compressor with zero frequency dispersion. Instead of a spherical telescope in the compressor, a cylindrical one is used. Due to large linear chirp in the input pulse, spectral profile corresponds to the temporal distribution.

We demonstrated in the experiment conversion of a 40 ps bell-shaped pulse into a rectangular pulse, demanded, for example, in photoinjector technology. Our scheme showed itself as a cheap and easy alternative to SLM shaping, therefore we believe it can be interesting for some applications. (paper)

[en] Short communication

[en] This study proposes a means for calculating the interaction force during the scanning process using a scanning near-field optical microscope (SNOM) probe. The determination of the interaction force in the scanning system is regarded as an inverse vibration problem. The conjugate gradient method is applied to treat the inverse problem using available displacement measurements. The results show that the conjugate gradient method is less sensitive to measurement errors and prior information on the functional form of quality was not required. Furthermore, the initial guesses for the interaction force can be arbitrarily chosen for the iteration process

[en] We experimentally demonstrate that the three-dimensional (3-D) shape variations of nanometer-scale objects can be resolved and measured with sub-nanometer scale sensitivity using conventional optical microscopes by analyzing 4-D optical data using the through-focus scanning optical microscopy (TSOM) method. These initial results show that TSOM-determined cross-sectional (3-D) shape differences of 30 nm–40 nm wide lines agree well with critical-dimension atomic force microscope measurements. The TSOM method showed a linewidth uncertainty of 1.22 nm (k = 2). Complex optical simulations are not needed for analysis using the TSOM method, making the process simple, economical, fast, and ideally suited for high volume nanomanufacturing process monitoring.

[en] For several decades there has been extensive research in the area of multiphoton spectroscopy. However, multiphoton processes have not found widespread applications due to the relatively low multiphoton absorption cross sections of most materials. A new generation of multifunctional organic materials with large multiphoton absorption cross sections has opened up a number of unique applications in photonics and biophotonics. Two-photon pumped upconversion lasing, multiphoton absorption-induced optical power limiting, multiphoton laser scanning microscopy, and two-photon three-dimensional optical data storage are some of the recent photonic applications of multiphoton processes highlighted in this article. Two-photon photodynamic therapy is another promising application to biophotonics which is also discussed here. (author)