We all know that in some specific fields, the required parameters of laser diodes are very high, so do you know how to classify laser diodes? Which industries need to meet the highest laser level? Let's take a look at it together

First, the common classification of laser diodes

Class 1

Equal to the "safety level", as long as it is under normal use conditions, there is basically no risk to the eyes. For example, the red laser head in a DVD player has a small power and is sealed in the shell, which is inaccessible to users.

Class 2

It is more common in visible light laser (400-700nm), and the power is ≤1mW, which is almost in this range like ordinary laser pen. It is generally okay to look straight for a short time, because the eyes will have natural blinking protection, but it is not recommended to stare.

Class 3R

The power is about 1~5mW, which is potentially dangerous to eyes, especially when magnified by optical instruments. Many small modules for ranging fall within this range.

Class 3B

When the power is from 5mW to several hundred mW, direct or reflected light may seriously harm eyes, and skin exposure for a long time may also be dangerous. Like lasers in scientific research laboratories, or some industrial diodes will reach this level.

Class 4

If the power goes up (hundreds of mW to hundreds of W or even higher), not only the eyes but also the skin is at risk, and it may also cause a fire. This is the common high-power laser used in industrial cutting and medical surgery.

Second, which industries should meet the high level?

Different applications have different requirements for grades:

1. Consumer electronics/daily necessities

Laser pen, laser toy, scanner, optical drive, etc.

Basically, it is limited to Class 1 or Class 2, because it is necessary to ensure the safety of public use.

If it is exceeded, a protective shell must be added to prevent the user from directly contacting the light beam.

2. Ranging/Sensing/Optical Communication

Laser rangefinder, dust detection, 3D scanning, self-driving lidar.

Most of them will be in Class 1 or 3R, because it involves the public environment, and both performance and safety should be taken into account. For example, laser radar for automobiles almost always requires Class 1, otherwise it is impossible to get on the road.

3. Industrial manufacturing

Laser welding, marking, cutting and additive manufacturing (3D printing)

Class 3B or Class 4 is commonly used because it requires high energy to process materials.

This kind of scene must have special protective cover, warning light and protective glasses.

4. Scientific research/laboratory

Class 3B or Class 4 laser sources are commonly used in research institutions and university laboratories.

There are high requirements for operator training and laboratory laser safety specifications.

5. Medical industry

Laser scalpel, ophthalmic surgery (myopia correction), dental laser treatment

Class 3B and Class 4 are common, because high energy is needed to act on tissues.

Hospitals must cooperate with strict safety regulations, and doctors and patients should wear goggles.

The closer the products are to ordinary consumers, the lower the grade requirements (mainly Class 1/2).

The more industrial, medical and scientific research, the higher the grade (3B/4 is essential).

In some sensor/ranging applications between the two, in order to find a balance between performance and safety, most of them will be stuck in level 1 or 3R.