1. Difference in Dielectric Materials
The difference between fiber lasers and semiconductor lasers lies in the different dielectric materials used to emit laser light. Fiber lasers use optical fibers as the gain medium, while semiconductor lasers use semiconductor materials, typically gallium arsenide (GaAs), indium gallium sulphide (InGaS), and other materials.
2. Difference in Luminescence Mechanisms
The luminescence mechanism of semiconductor lasers is the generation of photons by transitions between the conduction band and the valence band. Because they are semiconductors, electrical excitation is sufficient, resulting in direct electro-optical conversion. Fiber lasers, on the other hand, cannot directly achieve electro-optical conversion and require light to pump the gain medium (typically using a laser diode), achieving optical-optical conversion.
3. Difference in Heat Dissipation
Fiber lasers have excellent heat dissipation and can generally be cooled by air. Semiconductor lasers are significantly affected by temperature and require water cooling when the power is high.
4. Difference in Key Characteristics
The key characteristics of fiber lasers are their small size and flexibility. They produce multiple laser output lines, good monochromaticity, and a wide tuning range. Furthermore, their performance is independent of the polarization direction of the light, and coupling losses between the device and the fiber are low. High conversion efficiency and low laser threshold. The fiber geometry offers very low volume and surface area, and in single-mode operation, the laser and pump are well coupled.
Semiconductor lasers are easily integrated with other semiconductor devices. Their characteristics include direct electrical modulation, ease of optoelectronic integration with various optoelectronic devices, small size and light weight, low drive power and current, high efficiency, long operating life, compatibility with semiconductor manufacturing technologies, and mass production.
5. Diverse Applications
Fiber lasers are primarily used in laser fiber communications, laser space communications, industrial shipbuilding, automotive manufacturing, laser engraving, laser marking, laser cutting, printing roller manufacturing, metal and non-metal drilling, cutting, and welding (brass welding, quenching, cladding, and deep welding), military and national defense security, medical equipment, large-scale infrastructure, and as pump sources for other lasers.
Semiconductor lasers are widely used in laser ranging, lidar, laser communications, laser simulation weapons, laser warning, laser guidance and tracking, ignition and detonation, automatic control, and detection equipment.