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Transmission gratings have rarely been used for beam sampling because they require special properties from dielectric overcoatings, which, to the best of our knowledge, are described here for the first time. Although such gratings are often used as beam splitters, their nature can be modified along the same principles with thin metal coatings, which are described.

For lack of alternatives, echelle-grating diffraction behavior has in the past been modeled on scalar theory, despite observations that indicate significant deviations. To resolve this difficulty a detailed experimental, theoretical, and numerical study is performed for several echelles that work at low (8–13), medium (35–55), high (84–140), and very-high (to 660) diffraction orders. Noticeable deviations from the scalar model were detected both experimentally and numerically, on the basis of electromagnetic theory: (1) the shift of the observed blaze position was shown to decrease with the wavelength-to-period ratio, and it tends to zero more rapidly than the decrease of the maximum width, so that the TE- and TM-plane responses tend to merge into each other; (2) cut-off effects (Rayleigh anomalies) were found to play a significant role for high groove angles, where passing-off orders are close to the blaze order. A possibility for evaluation of the blaze angle from angular, rather than from spectral, measurements is discussed. Several reasons for the differences between real and ideal echelles (material-index deviations, profile deformations, and groove-angle errors) are analyzed, and their effects on the performance of echelles is studied.

Structural integrity in optical systems must be maintained to achieve submicron tolerances in optomechanical systems with moving parts—particularly important in microelectronics. Typical problems are illustrated with solutions.

An explanation is given for the effect of total absorption of light in grazing incidence by a sinusoidal grating, recently reported by us. The behavior of the zeros of both the first and the zeroth diffraction orders is studied numerically in the complex alpha plane. A link between the grating anomaly, non-Littrow perfect blazing, and plasmon excitation in relief metallic gratings is established. A total analysis of the behavior of the zeroth-order zero in grazing incidence is carried out, including groove depth, wavelength, and profile dependences.

The bulk of diffraction gratings used in the VUV and XUV regions are used at small angles of incidence and have shallow groove depths. Using rigorous electromagnetic theory, it is shown that such gratings behave in a scalar manner. It is then possible to derive universal efficiency curves from which one can obtain with simple rules the efficiencies of gratings with any metallic surface. The role of standard dielectric overcoatings is investigated and is found to be small. Some comparisons with experiments are given.

Recently developed rigorous theories have been used to investigate the diffraction efficiency behavior of both blazed and holographic gratings. In order to assist designers of spectrometric systems we have covered a complete range of blaze angles for triangular grooves and modulations for sinusoidal groove shape in first and second orders. Several types of mountings are included together with the role played by finite conductivity of aluminum. Useful classifications of both types of gratings are given, as they apply from the near uv to ir regions. Comparisons showing the close agreement between theory and experiment are presented.

Theoretical calculations predict that under certain special conditions a shallow fine pitch diffraction grating, given a precise dielectric overcoating, acts as a complete absorber of incident light of a specific wavelength and polarized in the P plane. Despite lack of a physical explanation, the phenomenon was confirmed by experiment.

Tests are described on new master echelles of very large size and on others having unusually high blaze angles, produced on interferometrically controlled ruling engines. Defects arising from the gravitational distortion of large grating blanks during ruling were reduced by the use of calibrated edge-supporting springs to diminish sag. The sixth echelle in a series of the largest yet produced (400 x 600 mm, or 16 x 24 in.), ruled on a fused silica blank 127 mm thick with 79 grooves/mm blazed at 63.4 degrees , gives high speed at resolutions well in excess of 10(6). A series of 254-mm echelles ruled at blaze angles whose tangents range from 2 to 8 were compared. Because an echelle blazed at 63 degrees can theoretically give 90% of the maximum resolving power available at any blaze angle, little resolution is gained by using steeper angles, and optical defects are likely to increase with groove asymmetry. Very high blaze angles are useful for raising intrinsic dispersion, however, making possible construction of echelle spectrometers of extreme compactness.

The development of grating ruling is presented in capsule form, from the first experiment of Rittenhouse in 1876 to the ruling of large echelles under interferometric control. The evolution of wavelength tables, especially in the United States, is described.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

The patent number, date of issuance by the U.S. Patent Office, and classification are shown on the first line. The filing date is that of the first application (although some patents may derive from earlier applications with earlier claim dates). Any opinions expressed are those of the reviewers and do not reflect the opinions of the organizations with which they are associated, the Optical Society of America, or this journal. Printed copies of these patents may be ordered from the Commissioner of Patents, Washington, DC 20231: telephone (703) 557-3158, URL http://patents.uspto.gov. Inquiries about patents should be addressed to the Patents Office, not to this journal or to OSA.

Rigorous electromagnetic theory is used to investigate the low order diffraction efficiency behavior of perfectly conducting rectangular groove plane diffraction gratings in the lambda/d domain of 0.25-1.8 of interest to spectrometry. We show how to optimize performance and make comparisons with blazed and holographic gratings. The role of finite conductivity and departure from Littrow conditions is also investigated. Comparison with experiment confirms the accuracy of the theory.

A detailed numerical study of the sinusoidal and triangular groove shape grating efficiency behavior has been carried out in grazing incidence using rigorous electromagnetic theory. The optimized parameters for maximum efficiency have been found for both types of grating. The influence of the metal reflectance and the oxide layer are discussed, and some results of higher order efficiency are also presented.

Total absorption of light by highly modulated metallic gratings is demonstrated both theoretically and experimentally. This phenomenon occurs when only the zeroth-order propagates and is linked with the excitation of surface plasmons.

The diffraction efficiency behavior of reflection gratings with an asymmetrical trapezoidal groove profile has been studied. Theoretical calculations predict that at certain grating parameters superior efficiency compared to the conventional ruled gratings can be achieved.

A heretofore unknown total absorption phenomenon on a diffraction grating has been demonstrated both theoretically and experimentally. It occurs only in a series of six special conditions, namely, groove shape, angle of incidence, groove frequency, depth modulation, polarization, and metal surface. None of the classical explanations for grating anomalous behavior seems to correspond to this case.