Antoni Drobnik

Multifiber laser Doppler velocimeter with backward scattering

A laser Doppler velocimeter (LDV) using a multi-fiber optic pickup was designed. A single fiber directs the beam to the moving surface. The back scattered signals were received by ten optical fibers. A multi-fiber laser Doppler velocimeter is (MFLDV) capable of determining the value of velocity as high as 10 mm/sec and as low as 0.031 mm/sec. A good linearity is obtained between Doppler shifted frequency (Delta) f and the velocity of a moving surface with a correlation factor of 0.999. LDV using fiber optics has important advantages over conventional systems, it is simpler, easier to align, and non-invasive i.e., the surface does not need to be touched or physically contacted.

Investigations of the phenomenon of light scattering on particles of atmospheric aerosols

atmospheric aerosols.Antoni DrobnikTechnical University of Lod, Institute of PhysicsWolczanska 219, 93-005 Lod, Poland.1. Introduction.The examinations of size distributions of atmospheric aerosols representthe important and timely problem both in science and in some fields of economy.The particulates of solid matter, drops of liquids or these both forms ofmatter simultaneously suspended in gaseous medium (usually in the air) form anaerosol. Continuous monitoring of sizes of atmospheric aerosols is necessary incertain scientific researches and in technological applications.Its known that suitably comminuted matter easier undergoes interactions with thesurrounding gas. The effectiveness of treatments with inhalations also dependson the degree of disintegration of the active substance in the air.

Certain results of the interaction of laser light with various media

The work presents the results of the investigations of the interaction of pulsed laser light with matter. The effects of this interaction that is the changes of dielectric constant and refractive index lead in turn to the phenomenon of self focusing of light. Light pulses in the irradiated materials can generate mechanical vibrations what makes the material inhomogeneous and increases the scattering process. Self focusing of light can be applied for the modulation of the action of pulsed lasers. The losses for caused by the mechanical vibration in optical fibers can be determined as a ratio of scattered energy flux (Sr ) and the energy flux of the fundamental mode (So). The interaction of powerful beams of laser light with various media can result in the changes of their physical properties. Laser beams with suitable temporal and spatial characteristics generate mechanical vibrations in the irradiated media 1 . . The investigations on the dynamics of the phenomena accompanying the interaction of strong optical pulses with irradiated materials made it generally possible to find out the causes of the generation of mechanical vibrations during such interactions 1 2 6 7 Absorbing materials when subjected to the action of laser light quickly get hot and deformed and afterwards the generation of series of mechanical pulses into and out of the sample can occur. As a result of the impact of laser pulses onto