Generation method and device for dual-spectrum femtosecond laser frequency comb

Abstract

The invention belongs to the fields of physics, optical engineering and measuring and testing technologies, and relates to a generation method and device for a dual-spectrum femtosecond laser frequency comb, in particular to a generation method and device for a dual-spectrum femtosecond laser frequency comb based on the difference frequency cavity principle. The device is simple in structure, low in cost and easy to obtain; according to method, extra-cavity dispersion compensation and pulse compression are carried out by using an extra-cavity dispersion compensation chirped mirror pair, the pulse width of a laser pulse generated by the difference frequency cavity femtosecond laser frequency comb is compressed to tens of femtoseconds again to obtain an optical frequency comb, wherein the pulse width of the laser pulse is increased to picoseconds because the laser pulse is transmitted in the air.

Description

technical field [0001] The invention relates to a method and device for generating a frequency comb of a dual-spectrum femtosecond laser, in particular to a method and device for generating a frequency comb of a dual-spectrum femtosecond laser based on the principle of a difference frequency cavity, belonging to the fields of physics and optical engineering And the field of metrology and testing technology. Background technique [0002] The femtosecond laser frequency comb using titanium-doped sapphire as the laser material can realize laser frequency measurement, but because the frequency doubling beat frequency method (also known as the f-2f method) is used in the process of locking the comb frequency to the atomic clock frequency, it needs The use of photonic crystal fibers usually results in a stable working time of only about 40 minutes. The femtosecond laser frequency comb offset frequency locking based on the improved difference-frequency cavity principle does not ne...

AI Technical Summary

Problems solved by technology

[0002] The femtosecond laser frequency comb using titanium-doped sapphire as the laser material can realize laser frequency measurement, but because the frequency doubling beat frequency method (also known as the f-2f method) is used in the process of locking the comb frequency to the atomic clock frequency, it needs The use of photonic crystal fibers results in a stable working time of only about 40 minutes

The femtosecond laser frequency comb offset frequency locking based on the improved difference-frequency cavity principle does not need to pass through the photonic crystal fiber to form a phase-locked loop, so it has the advantage of long stable working time compared with the f-2f method, and can work continuously and stably9 Hours or more, but since the radiation spectrum of titanium-doped sapphire ranges from 650nm to 1050nm, and the absorption spectrum ranges from 400nm to 600nm, the spectrum radiated from the laser cavity constructed by this laser material is usually about 650nm to 950nm, and it is difficult to include the spectrum below 650nm Therefore, the 633nm wavelength laser frequency commonly used as length measurement standards and instruments cannot be directly measured by the femtosecond laser frequency comb based on the difference frequency cavity principle

Images