We all know that laser diodes account for a large proportion in the market. Many people will wonder whether laser diodes are all eel, but they are not. There are many VCSEL lasers. Today, Xiaobian will introduce the difference between laser diodes EEL and VCSEL, and analyze the application scenarios for everyone.

EEL edge-emitting laser diode

EEL, the full name is Edge Emitting Laser, and the Chinese name is edge emitting laser diode. As the name implies, its laser comes from the edge of the chip.

The characteristics of EEL are very distinct:

High power: high energy density, concentrated emission direction, capable of outputting continuous or pulsed high-power laser.

Strong long-distance propagation ability: Because the divergence angle of light beam is small, it is especially suitable for long-distance measurement, light projection and marking.

High heat dissipation requirements: EEL has high power and heat, which requires a good heat dissipation structure, such as metal packaging or TEC temperature control.

Like our common industrial rangefinder, laser beauty instrument, bar code scanning, and even some optical communication modules, all use laser diodes with EEL structure.

VCSEL vertical cavity surface emitting laser

VCSEL, whose full name is vertical cavity surface emitting laser, is called vertical cavity surface emitting laser in Chinese.

Unlike EEL's "side emission", VCSEL's light is emitted vertically from the chip surface. In other words, it does not "shine from the side", but "shines from above".

This structure brings several significant advantages:

The beam divergence angle is smaller, and the light spot is more round and uniform;

Low power consumption, less heat generation and longer service life;

Easy to array, that is, many laser spots can be integrated on a chip.

This makes VCSEL shine in the field of consumer electronics.

For example, Apple's Face ID, laser focusing, 3D structured light, LiDAR, etc. are basically VCSEL. It can emit infrared light with accurate wavelength and stable power, which is safe for human eyes and can be used for area scanning, which is very suitable for 3D sensing and ranging.

From the technical point of view, these two kinds of laser diodes are like the two ends of the era. EEL supports industrial precision, and VCSEL promotes the intelligent future.