optical fiber ASE broadband light source module Manufacturers

Some laser applications require the laser to have a very narrow linewidth, that is, a narrow spectrum. Narrow linewidth lasers refer to single-frequency lasers, that is, there is a resonant cavity mode in the laser value, and the phase noise is very low, so the spectral purity is very high. Typically such lasers have very low intensity noise.

Since the invention of the world's first semiconductor laser in 1962, the semiconductor laser has undergone tremendous changes, greatly promoting the development of other science and technology, and is considered to be one of the greatest human inventions in the twentieth century. In the past ten years, semiconductor lasers have developed more rapidly and have become the fastest growing laser technology in the world. The application range of semiconductor lasers covers the entire field of optoelectronics and has become the core technology of today's optoelectronics science. Due to the advantages of small size, simple structure, low input energy, long life, easy modulation and low price, semiconductor lasers are widely used in the field of optoelectronics and have been highly valued by countries all over the world.

Since the advent of the first solid-state pulsed ruby laser, the development of lasers has been very rapid, and lasers with various working materials and operating modes have continued to appear. Lasers are classified in various ways:

Fiber lasers refer to lasers that use rare-earth-doped glass fibers as gain media. Fiber lasers can be developed on the basis of fiber amplifiers: high power density is easily formed in the fiber under the action of pump light, resulting in laser working material. The energy level "number inversion" can form laser oscillation output when a positive feedback loop (form a resonant cavity) is properly added.

The principle of lasers is based on stimulated emission, a concept first proposed by Einstein in the early 20th century. The main process is as follows.