Femtosecond Laser Synchronously Pumped High Power Broadband Degenerate Femtosecond Optical Parametric Oscillator

Abstract

The invention belongs to the technical field of lasers, and discloses a synchronous-pumping, high-power and wideband degenerated femtosecond optical parametric oscillator of a femtosecond laser. The femtosecond optical parametric oscillator comprises a 75.6MHZ Yb:KGW femtosecond laser pumping source, laser is given out from the pumping source, pass through a collimation focusing lens and then irradiates a Yb laser crystal, grain laser is oscillated and then irradiates a second concave mirror, the grain laser is sequentially reflected by the second concave mirror and a planar output mirror, isreturned along an original path and reaches the first concave mirror sequentially through the planar output mirror, the second concave mirror and the laser crystal, and the laser is reflected to a planar reflective mirror through the first concave mirror, is reflected to a planar reflective silver lens M1 through the planar reflective mirror and is output through the planar output mirror after oscillation. The maximum output power is 82mW, only 0.8% of root mean square fluctuates within 3.5 hours, the coverage range of 2-micrometer intermediate-infrared femtosecond laser spectrum which is output is 1,600-2,500 nanometers, and full width at half maximum is approximate to 450 nanometers.

Description

technical field [0001] The invention belongs to the technical field of lasers, in particular to a high-power broadband degenerate femtosecond optical parametric oscillator pumped synchronously by a femtosecond laser. Background technique [0002] Water has a strong absorption peak near the wavelength of 2 μm. The femtosecond light source in this band can not only be used for "eye-safe" remote sensing, but also for many applications such as the generation of high harmonics, driving particle acceleration, and optical frequency combs. Great attraction. Especially for optical frequency combs in the 2 μm band or above, they are widely used in many fields, including coherent molecular spectroscopy detection and trace gas detection. Currently, methods for generating ultrafast 2 μm pulses include Tm- or Ho-doped crystal-based mode-locked solid-state lasers, Tm-doped fiber lasers, and nonlinear parametric processes. Among them, both mode-locked solid-state lasers and fiber lasers a...

AI Technical Summary

Problems solved by technology

Therefore, broadband degenerate femtosecond OPO is the easiest way to generate a broadband optical frequency comb in the mid-infrared band. Although the 2μm ultrafast laser pulse width generated from broadband degenerate OPO can reach 48fs pulse, the spectral bandwidth is ultrafast 400nm (RudyCWet .al.Opticsexpress,2012,20(25):27589-27595.), but because its 2μm ultrafast laser is reflected by the output mirror inserted through the Brewster angle in the cavity, the average output power is only 10mW, and the corresponding single The comb power is too low, which greatly limits its application in optical frequency combs

[0003] In summary, the existing problems in the prior art are: (1) 2 μm ultrafast lasers produced by Tm-doped crystal-based solid-state lasers and Tm-doped fiber lasers are affected by the mode-locked technology, and their spectra are all Very narrow, only tens of nanometers, and the output power is about 30mW

(2) The current degenerate femtosecond OPO is reflected by inserting the output mirror at the Brewster angle in the cavity, and the average power is relatively low.

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