Differences between semiconductor lasers and fiber lasers:
(1) Different dielectric materials: One of the differences between fiber lasers and semiconductor lasers lies in the different dielectric materials they emit. Fiber lasers use fiber while semiconductor lasers use semiconductor materials, generally gallium arsenide and gallium applications.
(2) Different luminescence mechanism from the emitting machine of semiconductor lasers: Fiber lasers are equipped with the particle jumping photons between the conduction band and the price band. As it is a semiconductor, it can use electrical excitation, which is a direct electro-optic conversion. However, the optical fiber cannot achieve electro-optic conversion directly, so the optical pumping gain medium is required (usually the laser diode is used for pumping) to achieve the optical-to-optical conversion.
(3) Different heat dissipation performance: Fiber lasers have good heat dissipation and generally adopt air cooling, while semiconductor lasers are greatly affected by temperature and need water cooling when the power is high.
(4) Different characteristics: Fiber lasers are mainly featured with small volume and flexibility. Many spectral lines may be output from the laser, with good monochromism and wide tuning range. In addition, its performance has nothing to do with the direction of optical polarization, and the coupling loss between the equipment and the optical fiber is small. It has a high conversion efficiency low laser threshold. As the geometric shape, volume and surface area of the optical fiber are low, the laser can be fully coupled with the pump in a single-mode state. Semiconductor lasers can be easily integrated with other semiconductor devices. They have the characteristics of direct electric modulation, easy to integrate with various opto-electronic devices, small size, light weight, low driving power and current, high efficiency, long working life, compatible with semiconductor manufacturing technology, and being able produced on a large scale.
Main characteristics of fiber lasers:
(1) Fiber lasers have a small volume and flexibility.
(2) Many spectral lines may be output from the laser, with good monochromism and wide tuning range. In addition, its performance has nothing to do with the direction of optical polarization, and the coupling loss between the equipment and the optical fiber is small.
(3) It has a high conversion efficiency and low laser threshold. As the geometric shape, volume and surface area of the optical fiber are low, the laser can be fully coupled with the pump in a single-mode state.
Main characteristics of semiconductor lasers:
(1) They can be modulated directly.
(2) They are easy to integrate with various opto-electronic devices.
(3) They are small in size and light in weight.
(4) They have low driving power and current.
(5) They have high efficiency and long working life.
(6) They can be compatible with semiconductor manufacturing technology and produced on a large scale.
Semiconductor lasers are also widely used in laser welding, laser ranging, laser radar, laser communication, laser simulation weapons, laser warning, laser guidance and tracking, ignition and detonation, automatic control, detection instruments and so on.
Through the above analysis, one may comprehend the characteristic comparison between fiber lasers and semiconductor lasers. The characteristics of different types vary. In the process of practical application, the appropriate laser should be selected according to its own actual needs.
