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New physical objects, ispalators based on free soap films, exhibit persistent flows of the soap solution in open and closed volumes in air with additions of gases of the C8F18 type (p = 20 Torr) at temperature drops on the films of the order of tenths and hundredths of kelvin. The flows move continuously at a velocity of 5 — 20 cm s-1. It is found that the parts of an inclined ispalator film show anomalous behaviour upon heating: their weight increases and they move downward over the film, whereas the unheated parts of the film move upward. Continuous radial vortex flows accompanied by the formation and washing of the regions of a thin black film are observed on circular films in closed volumes upon their uniform external cooling by evaporating water for 5 — 10 hours. The rapid flows make film ispalators the efficient heat carriers, which operate at small temperature drops (tenths and hundredths of kelvin) and surpass copper in the amount of thermal energy being transferred. The outlook for the further study and applications of film ispalators for detecting thermal fields and laser radiation is discussed.

The unusual line structure observed earlier in the emission spectra of dye-laser liquid macrocavities is explained by the presence of transparent outer shells in which the generated and interfering laser radiation partly propagates, as in a complex cavity.

A continuation is reported of an investigation of new forms of liquid laser cavities and waveguides such as bubbles, menisci, and pendant drops. Lasing with a definite mode structure is predicted for pendant drops pumped by laser and incoherent radiations. The main features of the observed output radiation of totally reflecting closed cavities are considered.

Series of liquids are proposed for use as optical components, and as laser cavities and waveguides. Pulsed pumping of such cavities at λ = 532 nm resulted in lasing in the range 630–640 nm, which was investigated. Special features of liquid optical components used as sensors and employed in investigations of a variety of nonlinear processes were considered. The use of volatile fluoro-organic compounds, which reduce the surface tension when in contact with liquids, induced a self-organising capillary instability of optical and laser components with constant wave-like or chaotic motion of their surface layers.

An investigation was made of laser radiation coupling-out from totally reflecting closed liquid cavities by local frustration of total internal reflection with the aid of internal water spheres and external contact with a substrate or a prism. A rotating drop of ethanol containing rhodamine B in an envelope of liquid C₈F₁₈ generated laser radiation with a divergence of several angular degrees and an efficiency up to 5% relative to the excitation energy. A transparent drop of ethanol with rhodamine B, suspended in air, and subjected to uniform pumping was used to determine the depth of the zone in which lasing took place in a liquid cavity. An increase in the integral (during the pump time) fluorescence energy from a selected internal part of this drop, which did not participate in lasing, on increase in the excitation flux was in agreement with the expectations and it began to fall at high pump intensities. Characteristics of oscillations in immiscible liquids which evaporated in an evaporator — oscillator ('evapolator') were discussed.

It is found that narrow non-diverging laser tracks, earlier studied in free soap films, can also arise in thin rainbow films, e.g., of petrol, on water.

The results of the study of narrow laser tracks in soap films with the divergence below the diffraction-limited value are presented, and the mechanism of formation of narrow channels (spatial polariton solitons) based on laser dielectrophoresis in films is proposed.

When a 10 W — 3 W laser beam (for example, at 632.8 nm) is focused into a usual soap film of thickness between 10 nm and 10 m from the side or through a defect on the film surface, the self-channeling of the beam propagating in the film is observed. The beam also exhibits self-branching into submicron filaments, the so-called whiskers of length several tens of centimetres. The results of experiments on the dynamics of behaviour of these whiskers in a soap film, their polariton nature, and possible applications are discussed.

It is found that narrow non-diverging laser tracks, earlier studied in free soap films, can also arise in thin rainbow films, e.g., of petrol, on water.