Diffraction grating

About: Diffraction grating is a research topic. Over the lifetime, 24884 publications have been published within this topic receiving 372437 citations. The topic is also known as: grating.

Free-standing subwavelength metallic gratings for snapshot multispectral imaging

Abstract: A mosaic of ten spectral filters has been fabricated in a single 20 mm2 membrane drilled by nanoslits and coated by a gold layer. The nanostructured core-shell gratings exhibit 70% average maximum transmission efficiency in 15% aperture area, which represents a fivefold enhancement compared to the geometrical transmission. This mosaic of bandpass filters regularly spaced in the 3–5 μm wavelength range is used to demonstrate real-time spectral imaging in a multichannel camera.

Optical detection apparatus for detecting information relating to relative displacement of an object on whch a diffraction grating is formed

Abstract: An apparatus for optically detecting information relating to the relative displacement of an object on which a diffraction grating, arranged in two axial directions with a predetermined pitch. The apparatus includes a light-emitting device configured to emit a light beam, and a first optical element configured to divide the light beam from the light-emitting device into a plurality of light beams directed in each of the two axial directions to the diffraction grating on the object which produces a plurality of diffracted light beams for each of the two axial directions. The apparatus also includes a second optical element positioned and configured to receive and combine a plurality of diffracted light beams for each of the two axial directions from the diffraction grating on the object, and a plurality of detection units, each configured to receive and detect the combined plurality of diffracted light beams for one of the two axial directions, thereby detecting information relating to the relative displacement of the object in each of the two axial directions.

Injection molding and injection compression molding of three-beam grating of DVD pickup lens

Abstract: The objective of this paper is to investigate the application of injection molding and injection compression molding processes to produce diffraction gratings. A mold was designed to produce a diffraction rating connected with the fixed bushing. The combined part was verified to have a good diffraction performance. Integrated grating eliminates the assembly cost and error. Photolithography was applied to make the mold insert. The Taguchi method and parametric analysis were applied to study the effects of molding parameters on grating quality. The design, fabrication of structured mold surfaces and the results of the replication by injection molding (IM) and injection compression molding (ICM) are presented and compared. The diffraction angle of ICM grating is more accurate than that of IM grating. Grating made by ICM has a much smaller warpage than that made by IM. The diffraction pattern shows that ICM is a better process than IM to replicate a diffraction grating.

LiNbO(3) waveguide second-harmonic-generation device phase matched with a fan-out domain-inverted grating.

Abstract: A LiNbO(3) waveguide optical second-harmonic-generation (SHG) device, consisting of a channel waveguide array and a ferroelectric domain-inverted grating in a fan pattern for quasi-phase matching, is proposed. The structure has redundancy to absorb the residual phase mismatch caused by design uncertainties and fabrication errors. A SHG device of 3-mm interaction length was fabricated by domain inversion by Ti indiffusion and channel waveguide formation by annealed proton exchanging and reactive ion etching. A normalized SHG efficiency of 17%/W was experimentally obtained for pumping by a cw Nd:YAG laser.

Light-induced erasure of self-organized chi((2)) gratings in optical fibers.

Abstract: Self-organized χ(2) gratings in optical fiber, prepared by irradiating the fiber with 1.06-μm light from a Q-switched mode-locked Nd:YAG laser simultaneously with its second harmonic, can be erased optically. This is accomplished by irradiating the prepared fiber with the 532-nm mode-locked Q-switched light alone, without the 1.06-μm light, or with intense green or blue light from an argon laser. The erasure is reversible, and the fiber can be reprepared as before for second-harmonic conversion. The nonexponential time dependence of the erasure process can be explained by a model involving charge separation during seeding and recombination during erasure.