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.

Narrow line semiconductor laser using fibre grating

Abstract: A narrow linewidth, low chirp, wavelength selectable, packaged alternative to current DFB structures has been developed which employs a fibre reflection grating incorporated in the fibre pigtail. The wavelength of the packaged device can be determined by the appropriate choice of fibre grating coupled to the antireflection coated facet of a 1.55μm BH laser. Linewidths of less than 50 kHz, sidemode suppression of more than 30 dB and chirp when modulated at 1.2 Gbit/s of <0.5 MHz have been demonstrated.

Polymeric, electrically tunable diffraction grating based on artificial muscles.

Abstract: We demonstrate a low-cost, electrically tunable diffraction grating that is driven by a dielectric elastomer actuator. The angular tuning range of the polymer-based device is up to 118 mrad for the first diffracted order. The achievable grating period change of 32% is an improvement by more than a factor of 150 compared with existing analog tunable diffraction gratings based on hard materials. We show that in combination with a white light source, the presented diffraction grating can be used as a wavelength-adjustable luminous source. Such an illuminant has a potential application in inexpensive color displays that could reproduce all perceivable colors.

Fabrication and resonance wavelengths of long-period gratings written in a pure-silica photonic crystal fiber by the glass structure change

Abstract: It is shown that long-period gratings (LPGs) can be written in a pure-silica photonic crystal fiber without physical deformation by using the glass structure change. LPGs with different grating periods are made by the glass structure change induced by arc discharge. We find that the resonance wavelengths decrease with increasing the grating period in contrast with LPGs fabricated in conventional fibers. The second-order core mode begins to be supported in the long-wavelength region, and two resonance peaks appear there. This is due to a large increase of the index difference between the pure-silica core and the holey cladding against wavelength.

Ultra-high sensitivity accelerometers and gyroscopes using neutral atom matter-wave interferometry☆

Abstract: This paper shows that matter-wave interferometers employing low-velocity neutral atoms can be used as inertial sensors with sensitivities that exceed those of conventional mechanical sensors and multiple circuit optical interferometers by many powers of ten. The energy and mass dependence of the phase shifts that are due to rotation and acceleration are different. Thus a pair of interferometers with different energies and/or masses can perform simultaneous independent measurements of rotation and acceleration. A proposed configuration is one formed by a sequence of planar diffraction gratings operating in high order. Gratings consist of near-resonant standing-wave laser beams. Laser decelerated and cooled atomic beams provide a suitable source. Path curvature due to acceleration and rotation is canceled by magnetic field gradients that produce an effective magnetic levitation of the atoms in a feedback arrangement that maintains null phase shift.