Laser with adjustable power proportion and pulse interval and method

Abstract

The invention discloses a laser with adjustable power proportion and pulse interval and a method, which are used for realizing dual-wavelength near-infrared laser with the wave band of 1150-1200nm anddual-wavelength yellow light with the wave band of 575-600nm. A coaxial pumping structure is adopted, two laser gain media and a Raman crystal are utilized, dual-wavelength fundamental frequency light generated by the two laser gain media serves as an excitation source of a Raman laser, dual-wavelength Raman light operation is achieved, and on the basis, frequency doubling is conducted on dual-wavelength Raman laser in a cascade quasi-phase matching frequency doubling crystal; dual-wavelength yellow light output is realized. The power ratio and the pulse time interval of the dual-wavelength fundamental frequency light can be flexibly adjusted by changing the position of a pump light focus point in a laser gain medium or changing the wavelength of the pump light, and meanwhile, the power ratio and the pulse time interval of the dual-wavelength Raman laser can be adjusted by exciting the Raman laser in the cavity; and through out-of-cavity frequency multiplication, dual-wavelength frequency multiplication yellow light output with an adjustable power ratio and an adjustable pulse interval is realized.

Description

technical field [0001] The invention relates to the field of all-solid-state lasers and nonlinear optical frequency conversion, in particular to a dual-wavelength intracavity Raman laser with adjustable power ratio and pulse interval and a frequency-doubled dual-wavelength yellow laser. Background technique [0002] Dual-wavelength lasers have great scientific research value and broad application prospects in the fields of precision measurement, spectral analysis, remote sensing, and nonlinear frequency conversion. The coherent radiation source in the Hertzian band is an important research direction in the field of optoelectronics. [0003] The methods currently used to generate dual-wavelength laser output mainly include: [0004] 1. Two independent lasers are used to combine beams to form dual-wavelength lasers. However, this method has high cost and large volume and weight. If the two wavelengths are similar and the polarization directions are the same, it will be diffic...

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Problems solved by technology

[0004] 1. Use two independent lasers to combine beams to form dual-wavelength lasers, but this method is costly to implement and has a large volume and weight. If the two wavelengths are similar and the polarization directions are the same, it will be difficult to combine beams

In addition, for pulsed lasers, it is necessary to add a complex pulse synchronization system to achieve pulse synchronization or adjustable time interval of dual-wavelength lasers, and the overall structure is extremely complex (J.Opt.Soc.Am.B,2007,24(9) :2509-2516)

[0005] 2. Use a single-wavelength laser to excite two nonlinear crystals of different types, different cutting angles or different quasi-phase matching periods, and realize dual-wavelength laser output in an optical parametric oscillator through the second-order nonlinear effect of the crystal. This method Although the structure is simple and the cost is low, the power ratio and pulse interval of the output dual-wavelength laser cannot be tuned (Appl. Phys. Lett., 2016, 108(1): 011104)

[0006] 3. Use a single-wavelength laser to pump a double-resonant optical parametric oscillator composed of a crystal, so that the signal light and idler light of the optical parametric oscillator can be simultaneously oscillated and output, but this method generally only works on the phase matching curve Near the degeneracy point, and the tuning of the dual-wavelength laser power ratio and pulse interval cannot be realized (Opt.Express, 2016, 24(20): 23368–23375)

This method utilizes the second-order nonlinear effect of the crystal. Although the scheme is flexible, it is difficult to realize the dual-wavelength signal light close to the fundamental frequency light due to the limitation of the second-order nonlinear gain.

[0009] Generally speaking, there are shortcomings and deficiencies in the existing dual-wavelength laser technology: most implementations of dual-wavelength lasers have problems such as complex structure, high cost, and poor stability, and the power ratio and pulse interval of dual-wavelength signal light generally cannot be adjusted.

For the wavelength band (such as 1.1-1.2μm) close to the 1.06μm wavelength output by the Nd:YAG laser, it is difficult to realize it by the optical parametric oscillation technology due to the limitation of the second-order nonlinear gain, so it is also impossible to use the wavelength band (1.1-1.2μm) ) laser frequency doubling to produce double wavelength yellow light with adjustable power ratio and pulse interval

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