Focusing and deflection of optical beams by cylindrical mirrors.

An optical system incorporating two closely spaced cylindrical mirrors is described. By properly orienting the mirrors in space, an incident beam can be focused at any desired point within a large volume. This simple periscopic system, which provides variable focal lengths and deflection angles, is applicable to optical or millimeter wave transmission systems lying along irregular paths.

Degenerate Optical Cavities. III: Effect of Aberrations.

The capability of degenerate optical cavities to transmit faithfully incident optical signals with arbitrary wavefronts is limited primarily by geometrical optics aberrations. This capability is expressed by an acceptance factor which is calculated for various types of cavities lacking first-order degeneracy, or suffering from primary aberrations. It is found that the acceptance factors of spherically symmetric cavities are larger, by orders of magnitude, than the acceptance factors of cavities possessing only rotational symmetry (such as the well-known confocal cavity).

Degenerate Optical Cavities. II: Effect of Misalignments.

A simple expression is given for the response of degenerate cavities suffering from arbitrary misalignments, and numerical results are presented. The method of resonance excitation is carried out analytically with the help of a complex ray representation of gaussian beams. It is first shown that the modulus and phase of such complex rays can be identified with, respectively, the beam radius and the phase of the on-axis field.

Gaussian light beams with general astigmatism.

This paper considers the propagation and diffraction of coherent light beams through nonorthogonal optical systems such as sequences of astigmatic lenses oriented at oblique angles to each other. The fundamental (gaussian) mode has elliptical light spots in each beam cross section and ellipsoidal (or hyperboloidal) wavefronts near the axis. It is found that the orientation of the light spot differs from that of the wavefront, and changes continuously by as much as pi radians as the beam propagates through free space.

Degenerate optical cavities.

An optical cavity is degenerate when an arbitrary ray retraces its own path after a single round trip. The condition for degeneracy is given for ring type cavities incorporating internal lenses, using geometrical optics methods. The simplest linear configurations require a spherical mirror or a corner cube, a thin lens, and a plane mirror.