High-concentration Er3+ ions singly doped GaTaO4 single crystal for promising all-solid-state green laser and solid-state lighting applications

Exploring new visible laser crystals is of great significance to the development of diode pumped all-solid-state visible lasers and solid-state lightings. In this work, high concentration (10 at.%) Er3+ ions...

Adverse Health Effects of Exposure to Visible Laser Radiation in the General Population: A Review

Introduction: With the spread of laser technologies in various spheres of human activity, the number of exposures to laser radiation of a wide range of users unfamiliar with specifics of its health effects, including those in everyday life, has increased, thus resulting in an increased number of traumas in the general population in recent years. Objectives: To search for data on the biological mechanisms of action of visible laser radiation in Russian and foreign scientific literature and to analyze adverse health effects of this exposure encountered in domestic and international practice. Methods: We searched for Russian and foreign full-text open access literary sources in Russian Science Citation Index (RSCI) and PubMed databases of biomedical publications for 1969–2019 and selected the most appropriate ones for review. Results: Both Russian and foreign researchers note that human exposure to laser radiation induces specific and non-specific responses at all tissue levels of organization. The extent and nature of developing morphological changes depend on the radiation wavelength, exposure time, power, energy and its density per unit of the irradiated surface. Conclusions: Our findings suggest that portable laser pointers and powerful laser projectors may cause retinal damage, traumatic macular holes and, in some cases, loss of vision. Despite frequently registered good visual recovery, general availability of commercial laser devices poses potential danger, especially for minors, and substantiates the need to raise public awareness of laser safety.

A STUDY OF THE INFLUENCE OF 650 nm LASER INTERFERENCE ON VISIBLE LASER LIGHT COMMUNICATION SYSTEM

Visible Laser Light Communication System (VLLC) is a wireless communication system, using laser as the medium. In the data transfer process, it is possible to have optical interference where 2 laser beams coincide with one point on the reflector. Research on the effect of laser source interference has been carried out by several researchers including mitigation actions to reduce its effects. This experiment uses 2 optical distance sensors that produce a laser with a wavelength of 650 nm with a power <=4.1 mW and with the direction of the laser beam both of them cross each other. To determine the effect of the interference of two laser beams when crossing the communication process in the visible light communication system, a reflector is used which can capture the two laser beams and the reflector can be shifted gradually so that a condition can be obtained where the two laser beams meet at one point. From the measurements made at the points after the laser beam crossing, the measurements at the point where the beam crossed, and the measurements at the points before the beam crossing, it was obtained data, at the exact point where the laser beam crossed the interference occurred, which is indicated by unstable output voltage of the two lasers, so that communication at the point of intersection is disrupted. However, if outside the point of contact both before and after the point of contact, interference and communication systems will not occur.