Fiber-based single frequency blue-light pulsed laser

Abstract

The invention discloses a fiber-based single frequency blue-light pulsed laser comprising a pumping source, a beam combiner, a broadband fiber grating, thermoelectric coolers (TEC), an input collimator, a nonlinear crystal, a temperature control furnace, an output collimator, a high gain ytterbium-doped fiber, a narrow-band polarization maintaining fiber grating, PZT piezoelectric ceramic and a dichroic mirror. According to the fiber-based single frequency blue-light pulsed laser provided by the invention, fundamental frequency laser in a single longitudinal mode (single frequency) and with a wavelength of 960-980nm can be achieved based on a short linear tone Q-modulation manner and an inner cavity frequency doubling structure. The two TECs are used for adjusting temperature in a segmented manner, and the PZT piezoelectric ceramic is used for stretching out and drawing back to accurately control wavelength matching shapes of a fiber grating pair, so that losses in a resonant cavity can be modulated, and thus output of Q-modulation single frequency pulse fundamental frequency laser is achieved; and then harmonic conversion efficiency and output power of frequency doubling blue light are improved via the nonlinear crystal with length in centimeters and the inner cavity frequency doubling structure, and finally output of the single frequency blue-light pulsed laser based on a fiber manner is achieved.

Description

technical field [0001] The invention relates to a fiber laser, especially a single-frequency blue pulse laser for Q-switching based on centimeter-scale short linear cavity and inner cavity frequency doubling structure, using PZT piezoelectric ceramic electrostriction and thermoelectric cooler TEC segmental temperature control. Background technique [0002] Single-frequency fiber laser can operate in a single longitudinal mode state, not only has the characteristics of good heat dissipation, high efficiency, and compact structure of ordinary fiber lasers, but also has the advantages of narrow output spectral linewidth, low noise, and low threshold. However, in the case that the short-wavelength band (< 0.8 µm) lacks a gain medium and can directly generate laser light, second harmonic generation (SHG) frequency doubling is an effective means to obtain a short-wavelength laser source. In particular, the frequency-doubled 980nm single-mode laser can obtain the 490nm blue ligh...

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Problems solved by technology

[0004] Related patents are: (1) In 2013, Shandong Haifu Photonics Technology Co., Ltd. applied for a patent for a single-frequency pulsed blue light source [public number: CN 103545702A], which uses a piezoelectric element to periodically press the gain fiber to modulate 978nm fundamental frequency light The polarization direction is Q-switched, the nonlinear crystal is placed outside the resonator, and the external cavity frequency doubled single-frequency pulse blue light output is realized, but the required blue light laser does not have the characteristics of all-fiber, and the structure is more complicated

(2) In 2015, the Institute of Semiconductors of the Chinese Academy of Sciences applied for a patent on a tunable blue-ray laser device [publication number: CN 105428986A], using an 808nm semiconductor laser frequency-doubling sector-shaped polarization periodic crystal to realize a tunable frequency-doubling blue laser output , but the required blue laser does not have single frequency and pulse output characteristics

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