In order to deal with the conflicts between broad spectral region and high resolution in compact spectrometers based on a flat field concave holographic grating and line array CCD, we present a simple and practical method to design a flat field concave holographic grating that is capable of imaging a broad spectral region at a moderately high resolution. First, we discuss the principle of reali...

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 ...

The performance of three optoelectronic structures incorporating substrate-embedded InP-based inverted metal–semiconductor–metal photodetectors and/or volume holographic gratings are analyzed and compared at the primary optical communication wavelengths. These structures, in conjunction with optical-quality polymer layers, can be easily integrated into silicon microelectronic substrates for the...

In present work a compound holographic system consisting of a diffraction grating and a holographic lens has been fabricated to disperse and focus different portion of solar spectrum on laterally arranged solar cells of different band gaps to achieve maximum efficiency operation. Such concentrators are light–weight, low-cost and do not require tedious processing for their mass production.

Articles you may be interested in Dynamic characterizations of high diffraction efficiency in volume Bragg grating formed by holographic photopolymerization J.

Studies on the dynamics of holographic pattern formation in photosensitive polymers, gaining deeper insight into the specific material transformations, are essential for improvements in holographic recording as well as in integrated optics. Here we investigate the kinetics of volume hologram formation in an organic cationic ring-opening polymerization system. The time evolution of the grating s...

Performance of optical interconnects using volume holographic gratings and substrate-guided waves is subject to source wavelength detuning which originates from laser chirping and operating temperature changes. In this letter, we characterize and measure the dispersion of commonly used surface-normal volume holographic gratings. Dispersion characteristics of a 20 mm thick photopolymer volume ho...

MoRu-Be multilayer coatings were applied to two diffraction gratings for the purpose of enhancing their normal-incidence efficiency in the 11.1-12.0-nm wavelength range. The grating substrates were replicas of a holographic master grating that had a blazed groove profile with 2400 grooves/mm and a 2-m radius of curvature. The relatively low average microroughness (0.8 nm) of the grating surface...

A two-step method of writing high di raction efciency holographic gratings in photopolymer using just one writing beam during the second step is discussed. The technique is based on the use of weak gratings (<1%) recorded during a rst step which during the second step are illuminated with a single beam to form strong highly e cient holographic gratings. The weak grating provides a second interf...

We demonstrate that holographic Bragg reflector grating structures, which are photolithographically scribed in planar waveguides, support a unique approach to apodization and overlay that uses fixed-depth etching and partial contour writing to achieve continuous reflective amplitude control.