Results 111 to 120 of about 291 (152)

Blaze angle of the Bausch & Lomb R4 echelle grating

Applied Optics, 1983
On decrit une nouvelle determination de cet angle basee sur un modele pour le blaze des reseaux echelle qui s'ecarte de celle obtenue par Brown et al.
S, Engman, P, Lindblom
openaire   +2 more sources

The Production of Diffraction Gratings: II The Design of Echelle Gratings and Spectrographs1

Journal of the Optical Society of America, 1949
In seeking to circumvent the difficulties that have limited production of ruled gratings having resolving powers in excess of 400,000, it is observed that resolving power at a given wave-length depends only on the ruled width of the grating and the angles of illumination and observation, and not specifically on the number of ruled grooves.
openaire   +1 more source

Planar waveguide echelle gratings in silica-on-silicon

IEEE Photonics Technology Letters, 2004
Silica planar waveguide echelle grating demultiplexers with 48 channels and 256 channels are described and demonstrated. Polarization effects due to stress birefringence and polarization-dependent grating efficiency have been eliminated using a modified polarization compensator and grating design.
Janz, Siegfried, Balakrishnan, A., Charbonneau, Sylvain, Cheben, Pavel, Cloutier, Martin, Delâge, André, Dossou, K., Erickson, L., Gao, M., Krug, P. A., Lamontagne, Boris, Packirisamy, Muthukumaran, Pearson, M., Xu, Dan-Xia   +13 more
openaire   +1 more source

Echelle and holographic gratings compared for scattering and spectral resolution

Applied Optics, 1981
An echelle grating with 316 grooves/mm and a 63 degrees blaze angle is compared with a 3600-groove/mm holographic grating. The scattered light and resolution of the 10- x 20-cm gratings are photoelectricaly evaluated in a 3-m spectrometer optimized to eliminate coma and baffled to minimize instrumental scattered light. Both gratings are ghost-free, but
openaire   +2 more sources

A large mosaic echelle grating for ESPRESSO spectrograph

Optical and Infrared Interferometry and Imaging VI, 2018
ESPRESSO, The Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, is a super-stable Optical, fiber feed High Resolution Spectrograph for the combined coude focus of the VLT. The instrument has been successfully commissioned end of 2017.
Marco Riva, Denis Megevan, Francesco Alfonso Pepe, Antonio Ramon Manescau Hernandez, Johannes Klaas Dekker, Jean-Louis Lizon   +5 more
openaire   +1 more source

Perfect blazing with echelle gratings in TE and TM polarization

Optics Letters, 2012
Perfect blazing with echelle gratings in a high-order Littrow mount exists not only with TM polarization, as can perhaps be assumed, but also with TE and TM polarizations simultaneously. This finding contradicts with a heuristic explanation as to why perfect blazing is not possible simultaneously in TE and TM polarizations given by Loewen and Popov ...
openaire   +2 more sources

Effect of particle defects on an Echelle grating demultiplexer

Optics Communications, 2006
The impact of particle defects in the free propagation region on the performance of an etched diffraction grating demultiplexer is analyzed in the present paper. Numerical simulations using a method of moment and a Green function method show that particle defects with some special sizes can result in a strong resonance with the incident wavelength and ...
Xiaohua Cao, Dongyan Wang, Kang Li
openaire   +1 more source

Examination of the Spectral Efficiency of an Echelle Grating Monochromator

Applied Spectroscopy, 1979
The spectral efficiency of an echelle grating monochromator has been examined. The frequently cited advantage that “echelles are blazed at all wavelengths” is observed to be a result of the periodic character of the echelle efficiency as compared with the continually decreasing efficiency from the blaze wavelength for conventional gratings.
Andrew T. Zander, Peter N. Keliher
openaire   +1 more source

The Multi-Echelle Grating Arrangement (Mega) Spectrometer

SPIE Proceedings, 1984
A spectrometer system, based on the Multi-Echelle Grating Arrangement (MEGA) (1) has been developed. Through series diffraction in an even number of echelle gratings, high dispersion and spectral resolutions are obtained. It can be shown (1) that with n gratings of width W, utilized in a MEGA-spectrometer of focal length f, the same resolution and ...
openaire   +1 more source

Testing echelle gratings: a simple method

Applied Optics, 1987
S, Engman, P, Lindblom, B J, Olsson
openaire   +2 more sources