Patent ID: 11899229
Assignee: CHONGQING INSTITUTE OF EAST CHINA NORMAL UNIVERSITY
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for preparing a femtosecond optical filament interference direct writing volume grating or a chirped volume grating, wherein femtosecond pulse laser is configured to interfere in glass to form a section of optical filament that is several times a Rayleigh length of a light spot; a plasma, produced by multiphoton ionization of the medium caused by a femtosecond pulse laser, is controlled to rapidly scan in the glass and etch out a structure of the volume grating or the chirped volume grating by adjusting a focal length and laser energy of a focusing lens; and the femtosecond pulse laser has two or more beams, such that the two or more beams reunite at a focal point behind a converging lens after time domain synchronization to generate interference to form a plasma grating or a chirped plasma grating in the glass near the area of focal point.