Cadmium arsenide film-based passively mode-locked fiber laser

Abstract

The invention discloses a cadmium arsenide film-based passively mode-locked fiber laser. By adopting an annular cavity structure, a second end of a wavelength division multiplexer, a gain fiber (3), an isolator (4), an optical fiber coupler (5), a polarization controller (6), a cadmium arsenide saturable absorber (7), a single-mode fiber and a third end of the wavelength division multiplexer are sequentially connected to form a ring and the other end of the isolator is connected with an input end of the optical fiber coupler; a first output end of the optical fiber coupler is taken as pulse laser output, and a second output end is connected with the first end of the polarization controller in a loop; the other end of the polarization controller is connected with one end of the cadmium arsenide saturable absorber and the second end of the cadmium arsenide saturable absorber is connected with the first end of the single-mode fiber; and a pumping source injects pump light into the rare-earth-doped gain fiber in a coupling manner through the first end of the wavelength division multiplexer, namely a pump input end. By using the ultrafast saturable absorption characteristics of cadmium arsenide on near-infrared and mid-infrared bands, mode-locked pulse output of high pulse energy is achieved.

Description

technical field [0001] The invention relates to the fields of laser technology and nonlinear optics. In particular, a cadmium arsenide thin film passively mode-locked fiber laser. Background technique [0002] Pulsed lasers have extremely important applications in the fields of biomedicine, material processing, lidar, and communications. While maintaining the stability, conversion efficiency and beam quality of fiber lasers, pulsed fiber lasers have higher laser peak power than continuous wave fiber lasers, making them more widely used. At present, the main methods of realizing pulsed laser include Q-switching technology, mode-locking technology and gain switching technology, among which mode-locking technology is an effective means to realize high-peak ultrafast pulse. [0003] Passive mode-locking technology is one of the effective ways to realize mode-locked lasers. As a key part of passive mode-locking technology, saturable absorbers with optical Kerr effect have recei...

AI Technical Summary

Problems solved by technology

However, SESAM has the disadvantages of complex manufacturing process, high production cost, relatively narrow saturable absorption spectral range, and cannot work in the mid-infrared long-wavelength spectral region.

Although SWNT has the advantages of low production cost and wide saturable absorption spectrum compared with SESAM, the uncontrollability of its diameter when making SWNT saturable absorber will lead to inaccurate control of optical parameters and the introduction of additional insertion loss; graphene As a saturable absorber is an emerging passive mode-locking technology, it has problems such as low modulation depth and unobvious saturable absorption effect; molybdenum disulfide can also be used as a saturable absorber, but its saturable absorption effect has a large part Contribution from defect states, so repeatability and stability become the key factors restricting its development

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