Narrow-linewidth single-frequency thulium-doped distributed feedback fiber laser and system

Abstract

The invention relates to the technical field of optical signals, in particular to a narrow-linewidth single-frequency thulium-doped distributed feedback fiber laser and system. The narrow-linewidth single-frequency thulium-doped distributed feedback fiber laser comprises a thulium-doped fiber, a fiber bragg grating with phase shift is preset, the thulium-doped fiber is used for receiving a pump light signal, and when the pump light signal is transmitted to the phase shift grating, the phase shift grating forms laser oscillation based on the pump light signal and outputs a single-frequency laser signal; and the wavelength division multiplexer is arranged on a single-frequency laser signal output optical path track and is used for receiving the optical signal and outputting the optical signal to the phase shift grating, or is used for receiving the single-frequency laser signal and outputting the single-frequency laser signal along the single-frequency thulium-doped distributed optical fiber.

Description

technical field [0001] The invention relates to the field of laser technology, in particular to a narrow-linewidth single-frequency thulium-doped distributed feedback fiber laser and a system. Background technique [0002] Narrow-linewidth single-frequency laser has important application value in the fields of quantum optics, cold atomic physics, high-power laser systems, lidar and coherent communication due to its single-frequency characteristics, high spectral purity, and narrow laser linewidth. Among them, the research fields of quantum optics and cold atoms often have special requirements for the output wavelength in addition to the requirements of the linewidth of the single-frequency laser. Only when the photon energy corresponding to the wavelength of the single-frequency laser just satisfies the energy level difference can the application be realized. The specific wavelength required can range from the extreme ultraviolet band of 160nm to the far infrared band of 6um...

AI Technical Summary

Problems solved by technology

[0003] Existing technologies can use solid-state lasers, semiconductor lasers, fiber lasers and other types of lasers combined with different gain media and various nonlinear frequency conversion technologies to achieve narrow-linewidth single-frequency laser output in different bands, among which single-frequency Ti:Sapphire As the most mature solid-state single-frequency laser, the laser can achieve a watt-level single-frequency laser output near 800nm, and further combine nonlinear frequency conversion to extend the wavelength to the ultraviolet band, but the entire system is a full-space optical path structure, and there is a volume Large, poor stability, and susceptible to environmental interference; single-frequency semiconductor lasers can achieve single-frequency laser output in various bands by flexibly designing the PN junction interval in the chip, and are small in size and good in stability, but there is a problem of relatively low output power. Low disadvantage, in some cases can not meet the application requirements; single-frequency fiber laser generally adopts the structure of single-frequency seed laser plus fiber amplifier, by selecting different gains, it can already achieve high-power single-frequency laser output at 950-2200nm, But the power is not enough, further combining nonlinear frequency conversion technology can extend the wavelength to the whole band

However, in the thulium-doped fiber laser band, that is, 1700-2200nm, the existing technology only uses a single-frequency semiconductor seed laser combined with a fiber amplifier to output a single-frequency laser signal, but the output single-frequency laser linewidth is greater than 1MHz. In many applications unable to meet demand

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