Narrow linewidth laser

Abstract

The application discloses a narrow linewidth laser which includes: a passive ring-shaped waveguide; a first input and output waveguide that is passive and is coupled to the passive ring-shaped waveguide; a gain wave selection unit which is intended for obtaining gain for an entire laser and is configured to couple the light wave of selected wavelength and the passive ring-shaped waveguide; a second input and output waveguide that is passive and is coupled to the passive ring-shaped waveguide so as to allow the laser to transmit laser rays. According to the invention, the narrow linewidth laserhas a simple structure, does not cause connecting and coupling loss between a gain region and a waveguide region. The narrow linewidth laser uses integrated molding semiconductor technologies, has the characteristics of low device cost, and high stability and reliability, does not set limits to narrow linewidth that is caused by connecting and coupling, and can resist severe environment.

Description

technical field [0001] The present application relates to a laser, in particular to a narrow linewidth laser. Background technique [0002] Due to its excellent coherence, narrow linewidth lasers have become high-quality light sources for information communication (sensing), so they are of great application value. Not only can it be applied to cutting-edge scientific research such as high-precision spectral measurement and quantum (atomic) frequency standards, but it can also be applied to national defense and security fields such as laser ranging, laser radar, photoelectric countermeasures, and laser communication; it is also coherent optical communication, distributed optical fiber, etc. The core components of sensing are widely used in the fields of Internet of Things and high-speed communication. [0003] In view of its wide and attractive application prospects, many researchers and investment institutions have invested in the research of narrow linewidth lasers. Has e...

AI Technical Summary

Problems solved by technology

However, due to the limited cavity length of traditional DFB and DBR lasers, it is difficult to obtain extremely narrow linewidths even though complex grating structures are used to select wavelengths, which directly restricts their applications in the above fields.

[0009] In 2001, the United States proposed a weakly coupled ring external cavity semiconductor laser to achieve narrow linewidth, but due to too much loss in the ring, the single ring external cavity laser has not been realized (Appl. Phys. Lett., 79 (22) 3561, (2001 )

[0010] Although the above-mentioned lasers make full use of the extended cavity length of the ring resonator, the linewidth of the laser has been greatly improved compared with DFB and DBR, but all the structures here are not only based on the Si-based photonic integrated circuit as the linewidth narrowing unit, III- V SOA acts as a gain region, and the two are mixed and integrated to form a narrow linewidth semiconductor laser, and the Si-based photonic integrated circuit is very complicated, which reduces the yield of the device, and the materials of the docking hybrid integration are different, which inevitably introduces coupling loss, Polarization loss directly restricts the narrowing of the line width, and the change of this loss with the environment directly leads to poor reliability and stability, and poor resistance to harsh environments

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