Polymer optical fiber (POF) is one of the best transmission media for short-distance communications. To increase the transmission capacity of the fiber a wavelength-division-multiplexing (WDM) technique is commonly used. Several POF-WDM systems have been realized using interference filters and plane diffraction gratings as wavelength selective elements. In the present paper, for the first time ...

The chirp of single-cycle microwave fields after interaction with pairs of parallel diffraction gratings is measured in a phase-sensitive terahertz spectrometer. Novel transmission grating pairs recently proposed by Tournois, which combine diffraction and refraction effects, yield an almost linear group delay over a bandwidth that exceeds that of conventional reflection gratings by a factor of ...

The normal-incidence efficiencies of two 4800-grooves/mm ruled replica gratings, one with a dual-bandpass molybdenum/silicon multilayer coating and the other with a gold coating, were measured by use of synchrotron radiation in the 125-325-A wavelength region. The peak reflectance of the multilayer coating was 22% in the first Bragg order near 235 A and 28% in the second Bragg order near 126 A....

The diffusion of azo-dye (DR-1) in a planar liquid crystals host (5CB) at various temperatures has been investigated by laser-induced holographic grating relaxation technique. The decay of the diffraction intensity provides information about the diffusion of photoexcited azo-dye molecules. The relaxation time constants can be derived from the time dependence of the diffraction intensity fitted ...

We propose a fluorescence surface imaging system that presents a power of resolution beyond that of the diffraction limit without resorting to saturation effects or probe scanning. This is achieved by depositing the sample on an optimized periodically nanostructured substrate in a standard total internal reflection fluorescence microscope. The grating generates a high-spatial-frequency light gr...

Optical biosensors are a powerful method to detect biological analytes and typically measure the change of the refractive index caused by an analyte binding to the optical element [1]. Diffraction grating coupled based biosensors have many advantages including: easy integration, cost effective production and relatively high sensitivity [2]. The model of a novel grating coupled waveguide based b...

Thin holograms with novel diffraction properties were created in spectral hole-burning materials. Simultaneously sweeping the frequency of the recording light and the phase of the holograms results in an asymmetric distribution of diffraction efficiency between positive and negative orders. Experiments were performed that demonstrate amplified or attenuated diffraction efficiency with respect t...

Movement of a grating behind a fixed aperture can be detected by human subjects when the grating is well below the diffraction limit of the pupil and below acuity measured with stationary gratings. With movement one sees a flicker or ripple at the edges, and it is argued that these edge effects lead to spurious estimates of optical resolution in insects and man.

Large area Multilayer Dielectric (MLD) diffraction gratings are essential components for temporal pulse compression in high energy laser systems. MLD grating designs typically consist of a silica grating layer on top of a dielectric multilayer reflector. A reactive ion beam etching (RIBE) process using a gridded radio frequency (RF) ion source was developed to uniformly etch the silica grating ...

Vertical-cavity surface-emitting lasers (VCSELs) emitting at 894.6 nm wavelength have been fabricated for Cs-based atomic clock applications. For polarization control, a previously developed technique relying on the integration of a semiconducting surface grating in the top Bragg mirror of the VCSEL structure is employed. More specifically, we use a socalled inverted grating. The VCSELs are pol...