Femtosecond laser fiber spectroscopic device based on dispersion pre-compensation

Abstract

The invention provides a femtosecond laser fiber spectroscopic device based on dispersion pre-compensation, which comprises a femtosecond light source, a dispersion pre-compensator, a fiber coupling device and a fiber spectroscope. The femtosecond light source is used for generating seed laser with the pulse width in the magnitude of femtosecond, the dispersion pre-compensator is used for providing negative dispersion for the femtosecond laser generated by the femtosecond light source so as to compensate positive dispersion introduced into fiber transmission, the fiber coupling device is used for coupling the femtosecond laser which is outputted from the dispersion pre-compensator and carries the negative dispersion, and the fiber spectroscope is used for dividing laser coupled by the fiber coupling device into a plurality of channels of laser pulses to be outputted. The femtosecond laser fiber spectroscopic device has the advantages that the femtosecond pulses with the pulse width close to that of the seed laser can be obtained at a fiber output end, the spectrum and the waveform of the pulses can be kept beneficially after the pulses are transmitted in an optical fiber, the provided negative dispersion can be changed, and accordingly the pulse width of laser outputted after optical fiber transmission is adjusted.

Description

technical field [0001] The invention relates to the technical field of femtosecond laser technology and optical fiber transmission, in particular to a femtosecond laser optical fiber splitting device. Background technique [0002] Since the successful realization of Kerr lens mode-locking of titanium-doped sapphire lasers in the 1990s, femtosecond lasers, as the shortest time-scale laser pulses that humans can obtain from simple solid-state lasers, have been obtained in many fields of science and technology. a wide range of applications. The extremely short duration of the femtosecond laser can be used as an ultrafast probe to study the transient process of the material world, such as high-precision multi-photon excitation fluorescence detection in biology, the synthesis of chlorophyll, and many other chemical processes that occur on the femtosecond time scale. reaction. In 1995, the Swedish scientist Zewail used a femtosecond probe to observe the bonding and breaking proc...

AI Technical Summary

Problems solved by technology

However, for optical fiber transmission of femtosecond pulses, due to the wide spectrum of femtosecond ultrashort pulses, each frequency component will cause pulse width broadening due to different phase velocities when propagating in a dispersive medium, such as for 780nm, 30fs The ultra-short pulse laser is propagated through 1m standard single-mode fiber, and the laser pulse width is broadened to more than 1ps due to positive dispersion during output, which is unbearable for applications that require femtosecond lasers, and directly converts the 30fs The ultra-short pulse is focused into the fiber core, and the extremely high peak power will cause the nonlinear effect of the laser in the fiber, which will affect the spectrum and waveform of the output pulse. This was proposed by B.W.Atherton and M.K.Reed in 1998 Described in "in Commercial Applications of Ultrafast Lasers" published in Proceedings of the International Society for Optical Engineering 3269, 22

[0005] To solve these problems, researchers have proposed some solutions, for example in Opt. Lett. 27 pp. 1513-1515 (2002) by D.G.Ouzounov, K.D.Moll, M.A. Proposed in "Delivery of nanojoule femtosecond pulses through large-core microstructured fibers", it is possible to use specially designed fibers with special linear and nonlinear properties to compensate for pulse distortion, but the high cost of making special fibers makes it impossible Promote application

Images