Which of the following is one of the five classes of LASER?

The correct choice is Class 1, as it represents one of the five established classes of LASERs, classified primarily based on their potential hazard to the eye and skin. Class 1 LASERs are considered safe under normal operating conditions and do not pose a threat of injury even with prolonged exposure, making them suitable for everyday applications. This classification helps ensure that users understand the safety precautions necessary when working with different types of LASER technology.

The other classes, while also valid within the framework of LASER classifications, represent varying levels of hazards. Class 2 and Class 3B, for instance, require more care during operation due to risks from direct exposure to the beam. Class 4 represents high-powered LASER devices that can cause severe injuries and require stringent safety measures. Understanding these classifications is crucial for operational safety and compliance with regulations in environments where LASERs are used.