Class Of Optical Systems Research Articles

At-will chromatic dispersion by prescribing light trajectories with cascaded metasurfaces

Chromatic dispersion spatially separates white light into colours, producing rainbows and similar effects. Detrimental to imaging but essential to spectroscopy, chromatic dispersion is the result of material properties in refractive optics and is considered an inherent characteristic of diffractive devices such as gratings and flat lenses. Here, we present a fundamental relation connecting an optical system’s dispersion to the trajectories light takes through it and show that arbitrary control over dispersion may be achieved by prescribing specific trajectories, even in diffractive systems. Using cascaded metasurfaces (2D arrays of sub-micron scatterers) to direct light along predetermined trajectories, we present an achromatic twisted metalens and experimentally demonstrate beam deflectors with arbitrary dispersion. This new insight and design approach usher in a new class of optical systems with wide-ranging applications.

Reflecting anastigmatic optical systems: a retrospective

Reflecting anastigmatic optical systems hold several inherent advantages over refracting equivalents, such as compactness, absence of color, high “refractive efficiency,” wide bandwidth, and size scalability to enormous apertures. Such advantages have led to these systems becoming, increasingly since their first deliberate development in 1905, the “go-to” solution for various classes of optical design problems. This paper describes in broad terms the history of the development of this class of optical system, with an emphasis on the early history.

Role of geometry in the superfluid flow of nonlocal photon fluids

Recent work has unveiled a new class of optical systems that can exhibit the characteristic features of superfluidity. One such system relies on the repulsive photon-photon interaction that is mediated by a thermal optical nonlinearity and is therefore inherently nonlocal due to thermal diffusion. Here we investigate how such a nonlocal interaction, which at a first inspection would not be expected to lead to superfluid behavior, may be tailored by acting upon the geometry of the photon fluid itself. Our models and measurements show that restricting the laser profile and hence the photon fluid to a strongly elliptical geometry modifies thermal diffusion along the major beam axis and reduces the effective nonlocal interaction length by two orders of magnitude. This in turn enables the system to display a characteristic trait of superfluid flow: the nucleation of quantized vortices in the flow past an extended physical obstacle. These results are general and apply to other nonlocal fluids, such as dipolar Bose-Einstein condensates, and show that "thermal" photon superfluids provide an exciting and novel experimental environment for probing the nature of superfluidity, with applications to the study of quantum turbulence and analogue gravity.

Techno-economic aspects of aspherization of optical elements in optical systems

The creation of modern optical and optoelectronic devices requires the use of progressive design and process solutions, one of which is the aspherization of optical surfaces, which is directed to reaching the limiting characteristics of optical systems. Because of this, it is necessary to use a comprehensive approach not only to the design problems and to the development of processes and methods for monitoring the production of aspheric surfaces, but also the techno-economic bases for using them. This article discusses the techno-economic conditions for the validity of the aspherization of optical elements for creating various classes of optical systems.

On the uniqueness of optical images and solutions of inverse lithographical problems

We analyze the uniqueness of the solutions of inverse lithographical problems, stated as optimization problems, and optical images. By considering a band-limitedness argument, examples of ill-posed problems are constructed with multiple solutions in the domain of real non-negative passive masks. We conclude that the necessary condition for the solution m to be unique is to touch (or to pass infinitely close to) the boundary of the constraint 0m1. In the domain of binary masks, we propose a procedure to construct two nonunique solutions from a possibly unique one. We prove the existence of unique binary solutions in some class of optical systems and suggest a thresholding procedure to generate a unique solution from a possibly nonunique one.

Edward George Sydney Paige. 18 July 1930 — 20 February 2004

Professor E. G. S. Paige was an applied physicist who spent the first half of his career at the Radar Research Establishment, Malvern, where he made major contributions to the understanding of transport properties in semiconductors. He is, however, particularly celebrated for his work there on acoustic surface waves and their use in electronic systems. In a later period while at Oxford he developed an innovative class of optical systems based on the use of programmable phase plates.

Superluminal propagation in resonant dissipative media

We analyse the superluminal propagation of optical narrow-band pulses at resonances in dissipative media. We find that, for a broad class of optical systems holding this type of lossy faster-than-light transmission capability, the output waveform is an attenuated, time-advanced version of the input which can be interpreted as the result of the interference of two scaled replicas of the input having a positive relative delay. This analysis is shown to apply, among other scenarios, both in the propagation in a passive bulk medium at an electronic resonance and in a dielectric waveguide coupled to a lossy micro-ring resonator.

Conformal dome correction with counterrotating phase plates

Windows and domes that are shaped to aerodynamic requirements can increase range and speed for the host platform. This class of optical systems is referred to as conformal optics. The solution discussed here is intended for conformal missile systems having gimbals that point the optical line of sight through different parts of the dome. A conformal dome induces large amounts of varying aberration, tens to hundreds of waves across gimbal angle, and therefore requires dynamic correction. Space is very constricted in missile sensors, and it is therefore highly desirable to limit the number of motors used for aberration correction. This paper describes the performance of a new class of optical systems that employ counterrotating phase prisms to correct conformal dome aberrations while gimbaling the optical system. The phase surfaces on the prisms are described by Zernike circular polynomials. Since the shear across the phase surfaces is rotational, the only aberrations that are generated are those without rotational symmetry, such as tilt, coma, or astigmatism. Using this approach, CODE V® was used to analyze and design a compact, high-performance conformal optical system.

Noiseless amplification in cavity-based optical systems with an internal two-photon process. I. General approach

We study the features of noiseless amplification in a general class of optical systems, characterized by an intracavity nonlinearity which induces a two-photon process, in the limit where the damping constant of the mode which undergoes the two-photon process greatly exceeds all other relaxation rates of the system. By applying a previously formulated analytical approach, we write the universal-form expressions for the linear amplification factor and the noise figure. Noiseless amplification is attainable under resonance conditions.

Optical realization of the baker's transformation

The quantization of a completely chaotic system-the baker's transformation-is investigated using the fact that the relationship between classical and quantum mechanics is directly analogous to the one between ray and wave optics. A class of optical systems is constructed for which the ray dynamics is governed by the baker map. Applying wave-optical methods to these physical systems then gives, in the standard way, their corresponding quantum dynamics. The result is that in certain cases the quantum propagator is identical to that found previously using an ad hoc mathematical quantization procedure. However, this is not always so-for other systems with the same classical (ray) limit there are important differences. In particular, the propagator need not be block-diagonal in its q-p' representation, as had previously been assumed, although it always tends to this basic form in the semiclassical limit.

A Wave Theory for Non-imaging Concentrators

Abstract An expression is found for the propagation of the radiance function for light in any state of coherence through a concentrator which can be represented by a linear, stationary optical system. For light from a quasi-homogeneous source this expression can be somewhat simplified by an approximation. It is shown that the radiance function is invariant for a large class of optical systems. Finally it is shown that fundamental limitations for the concentration of light follow from the uncertainty principle and the second law of thermodynamics, which apply quite generally. These relations show why quasi-homogeneous light (i.e. light from thermal sources) cannot be concentrated as well as light from some other sources (such as light from a laser).

Universal normal-form description of squeezing and instabilities in two-photon processes

We consider a class of optical systems, consisting of an electromagnetic resonator, a two-photon medium and a single-mode cavity field, in the limit when the field decay constant out of the cavity greatly exceeds the remaining relaxation rates. Under rather general conditions, this limit favors the emergence of self-oscillations over a finite domain of parameter space where, for resonant interaction, the instability has a pure phase or amplitude character. The squeezing of the quadrature component of the output field that is orthogonal to the unstable component approaches the ideal limit in the vicinity of the instability threshold and its spectrum can be described by a simple and universal normal-form. We analyze selected configurations of experimental interest and identify a new type of instability that should emerge in four-wave mixing cavities with a concomitant large squeezing effect; we show also that the phase instability and squeezing recently predicted in two-photon optical bistability persist even after inclusion in the model of the effects associated with the intensity-dependent Stark shift.

Aberrations of a sequence of conic mirrors

An interesting class of optical systems consists of conic mirrors arranged so that each mirror shares at least one focus with the optically adjacent mirrors. This paper presents simple results for several of the aberrations largely independent of the details of the configuration. Results are presented for sine law violation and third order astigmatism when the images are located at the focii of the mirrors and for astigmatism and distortion when the pupils are located at the foci. In both cases the system is equivalent to a single conic mirror having the same magnification and focal length. It is shown that there are configurations for which both the images and the pupils lie at foci, and for these all the above results apply. The exact shape of the image surface is obtained for such a system in which all the mirrors are parabolas.

Matrix Analysis of Gimbaled Mirror and Prism Systems*

This paper shows a general matrix method for analyzing systems of gimbaled mirrors, prisms, and ray projectors. The method shows how to find the gimbal angles which are necessary to ensure that a ray traversing the system obeys some requirement of collimation or orientation. Gimbal angles are considered to be the important measurement parameters, and more meaningful than the usual direction cosines. The methods apply to a large class of optical systems, including those in which gimbals are not specifically used. The gimbal concept will be found very useful in describing the orientation of images in prism systems, such as the peculiar behavior of a penta prism. A gimbal operator is defined and used throughout. The appendix contains a formal development of the mirror as a second-rank tensor together with important properties of prisms as products of mirror matrices.