A COMPARATIVE STUDY ON THE COHERENCE AND DIRECTIONALITY OF HELIUM-NEON AND SEMICONDUCTOR LASERS

Abstract

This study presents a comparative analysis of the beam divergence angle and wavelength between semiconductor and Helium-Neon lasers. The researchers conducted both theoretical and experimental measurements of the two types of lasers, and the experimental results were compared to the theoretical ones. Ten trials were conducted in three orders, ranging from 20cm to 200cm with 20cm intervals for each order. The study found that in the first and second orders, the Helium-Neon laser had a greater wavelength and divergence angle compared to the semiconductor laser, indicating that the latter is highly directional and intense. However, in the third order, the Helium-Neon laser was not visible, suggesting that it was not highly directional. The study also found an inverse relationship between beam divergence angle and wavelength for the two types of lasers.

The experimental analysis was conducted in the physics department laboratory at Debre Markos University using a grating element, holder, ruler, screen, Helium-Neon laser, and semiconductor laser. The results of the study agreed with the theoretical results, suggesting that the experiment was well-conducted.

Keywords: beam divergence angle, directionality, Helium-Neon laser, semiconductor laser, wavelength.