Powerful Laser Diode Matrixes for Active Vision Systems
— This article is deal with the experimental investigations of the laser diode matrixes (LDM) based on the AlGaAs/GaAs heterostructures (lasing wavelength 790-880 nm) to find optimal LDM parameters for active vision systems. In particular, the dependence of LDM radiation pulse power on the pulse duration and LDA active layer heating as well as the LDM radiation divergence are discussed.
Active Pulse Vision Systems and Algorithms for Determining Distances to Objects
It is found analytically and experimentally that four characteristic distances intervals can generally be distinguished in the formation of images of objects in active pulse vision systems. A physical interpretation of their origin is given. Four algorithms are proposed for determining the distance to objects using the characteristic distances or for measuring calibration constants. The depth of the visibility zone is found to depend on the sum of the durations of the laser illumination pulse and the strobe pulse of the receiver system.
Measurement and Demonstration of Thermal Expansion Coefficient
There are many classroom demonstrations, such as the ball-and-ring experiment, for showing the existence of thermal expansion of solids. The coefficient of linear expansion α (= increase in length divided by the original length times the change in temperature) may be measured in high school laboratories using a number of methods.1–4 In this paper we describe an especially simple experiment for determining α for a metal rod. It is based on the well-known optical lever method and is suitable for either a laboratory experiment or a classroom exercise.