A simple laser teaching aid for transverse mode structure demonstration

Abstract

A teaching aid for demonstrating the transverse mode structure in lasers is described. A novel device called 'multi-dimension adjustable combined cateye reflector' has been constructed from easily available materials to form a He-Ne laser resonator. By finely adjusting the cat-eye, the boundary conditions of the laser cavity can be altered, which allows the transverse modes output by laser to be conveniently modulated. Equipped with a CCD imaging system, this apparatus allows more than 20 laser transverse modes to be visualized on the computer screen, provided a valuable teaching aid at an undergraduate level.

Laser experimental system as teaching aid for demonstrating basic phenomena of laser feedback

“…Since the research and applications above are linked to the laser feedback, its basic phenomena and characteristics should be illustrated clearly to students in undergraduate teaching classes, especially in a class on laser physics. However, most classrooms have experimental systems used for demonstrating the principles of lasers such as laser transverse mode and longitudinal mode [14,15], but rarely have an efficient device to observe various laser feedback phenomena. Moreover, students are usually instructed to avoid laser feedback by using an isolator in an optical system.…”