Single-mirror System Research Articles

Study on the design and Zernike aberrations of a segmented mirror telescope

The segmented mirror telescope is widely used. The aberrations of segmented mirror systems are different from single mirror systems. This paper uses the Fourier optics theory to analyse the Zernike aberrations of segmented mirror systems. It concludes that the Zernike aberrations of segmented mirror systems obey the linearity theorem. The design of a segmented space telescope and segmented schemes are discussed, and its optical model is constructed. The computer simulation experiment is performed with this optical model to verify the suppositions. The experimental results confirm the correctness of the model.

Performance analysis of laser projection systems of different configurations

Starting with ray tracing through a single-mirror beam steering system, an analytical approach is developed to predict the scan pattern on a flat screen. The results for a single-mirror system are then extended to a two-mirror/two-axis beam scanning system, which paves the way to a performance comparison of single-mirror and two-mirror/two-axis laser projection systems. Some fundamental aspects of mirror-based laser projectors of different configurations are investigated, such as maximization of image size on screens of different format, the effect of pixel rotation and size changes on image resolution, and the relationship of angular motion of the mirror in a single-mirror system and the two mirrors in a two-mirror/two-axis system.

Single-mirror beam steering system: analysis and synthesis of high-order conic-section scan patterns

The vector approach introduced in an early paper for modeling mirror-scanning devices [Y. Li, Appl. Opt. 34, 6417 (1995)] provides the basis of a rigorous study of the scan field generated by a single-mirror beam steering system, in which a hinged movable mirror is able to turn about a fixed pivot point to steering a single laser beam. Because of fewer constraints on mirror angular motion, the system may behave like a true point source for both vector and raster scanning applications. After a summary of the expressions for scan fields generated under different conditions, some fundamental and advanced topics of the single-mirror system are addressed: (1) basic parameters of high-order conic-section scan patterns, (2) scanning spot kinematics, (3) effect of input offset and pixels distortions on two-dimensional images displayed on screens of different formats, (4) mapping and its inverse between the mirror vector space and the scan vector space, and (5) single-mirror beam steering system as a one-element reflective and continuous image zooming device.

Nonequilateral drifting hexagons in a strongly misaligned single-mirror system

We report on the appearance of a new type of pattern in an optical pattern-forming system consisting of sodium vapour as a nonlinear medium and a single feedback mirror. These patterns are drifting and stationary nonequilateral hexagons which appear if the feedback mirror is strongly tilted. They are due to the resonant coupling of static and oscillatory wavevectors lying in different instability balloons and thus constitute a special example for the recently predicted Hopf-static structures.

Concentration Ratios for Flat-Plate Solar Collectors with Adjustable Flat Mirrors

Flat mirrors are frequently used to increase the heat output from flat-plate collectors. They are generally oriented in an east-west direction and are mounted below and/or above the collector panels. The annual performance of a mirror-boosted system can be improved by allowing periodic adjustments of the mirrors alone or of the panel-mirror units. In order to compare different mirror-panel configurations their solar flux concentration ratios are averaged over a yearly period using the solar elevation angle time probability function. AH configurations have the same ratio of mirror area to panel area. In general, it is found that the mirror orientations are more important than the panel orientations. Seasonal adjustments of the mirrors suffice to maintain acceptable values of the concentration and there is relatively little advantage in providing for collector panel adjustments. For year-round collection configurations with semiannual mirror adjustments provide a marked increase in output relative to fixed configurations. A double-mirror system (adjustable trough) provides higher concentrations than a single-mirror system for equal mirror area. Adjustable trough configurations with zero acceptance angle provide higher annual average concentration ratios than those with non-zero acceptance angles.

Über die Ausleuchtung von Spektrographen

In order to match the optical efficiency of a spectrograph the external light -collecting system should have a light-gathering power not less than that of the spectrograph itself. The geometrical conditions for this are fulfilled by the arrangement of lenses recommended by Zeiss. Improvements are possible by reducing the light-losses in the external system through reflections and through chromatic aberration by substituting a two-mirror system or even a single-mirror system for the lenses. In either case another concave mirror behind the source has advantages for quantitative spectral analysis. Finally the proposal of E. preuss to use an array of lenses to eliminate the effect of the movements of the light-source on the illumination of the spectrograph is described.

Lloyd's single-mirror interference fringes

Half of the central fringe of Lloyd's single-mirror system can be seen directly if the fringes are observed in a plane passing through the edge of the mirrors, and if the mirror is of ordinary, not black, glass and has a cleanly cut edge which is illuminated by light shining on to the opposite edge. The use of mica to displace the fringe system is not valid, since the central fringe will be displaced more for blue light than for red. This dispersion of the central fringes for the different colours may produce a displaced white-light system approximately symmetrical about a black fringe, but this black fringe will not be produced by the coincidence of the displaced central fringes. It is equally possible to find a thickness of mica which gives a displaced system symmetrical about a white fringe. The phase change on reflection at a less dense medium at grazing incidence is shown to be in the region of π, since a system with a black central fringe is formed when the mirror is immersed in carbon bisulphide.