Femtosecond laser system for processing micro-hole array

Patent metadata

Field	Value
Publication number	US-2022016729-A1
Application number	US-202117489275-A
Country	US
Kind code	A1
Filing date	Sep 29, 2021
Priority date	Apr 15, 2019
Publication date	Jan 20, 2022
Grant date	—

Abstract

Provided is a femtosecond laser system for processing a micro-hole array, comprising: a femtosecond laser, a half-wave plate, a polarizer, a concave lens, a convex lens, a diaphragm, a mechanical shutter, a phase-type spatial light modulator, a first plano-convex lens, a reflecting mirror, a second plano-convex lens, a dichroic mirror, a camera, a processing objective lens, a six-axis translation stage and a transmissive white light source.

First claim

What is claimed is:

1 . A femtosecond laser system for processing a micro-hole array, comprising: a femtosecond laser, a half-wave plate, a polarizer, a concave lens, a convex lens, a diaphragm, a mechanical shutter, a phase-type spatial light modulator, a first plano-convex lens, a reflecting mirror, a second plano-convex lens, a dichroic mirror, a camera, a processing objective lens, a six-axis translation stage and a transmissive white light source;
wherein the femtosecond laser, the half-wave plate, the polarizer, the concave lens, the convex lens, the diaphragm and the mechanical shutter are sequentially arranged on a first optical axis; wherein the mechanical shutter is configured to control a femtosecond laser beam to be incident on the phase-type spatial light modulator to generate a spatially shaped femtosecond laser pulse; wherein the spatially shaped femtosecond laser pulse sequentially passes through the first plano-convex lens, the reflecting mirror, the second plano-convex lens and the dichroic mirror to reach the processing objective lens, and is focused by the processing objective lens to be irradiated on a sample to be processed on the six-axis translation stage to form the micro-hole array for the sample; wherein the half-wave plate and the polarizer together constitute an energy adjustment system for adjusting energy of the femtosecond laser and making a polarization direction of the emitted femtosecond laser beam horizontal; wherein the phase-type spatial light modulator is configured to perform phase modulation to the femtosecond laser beam according to a phase diagram of the micro-hole array of the sample; wherein the concave lens, the convex lens and the diaphragm together constitute a beam expansion system for adjusting a beam waist diameter of the femtosecond laser beam, wherein a front focus of the concave lens and a front focus of the convex lens coincide with each other; wherein the dichroic mirror, the camera located at one side of the dichroic mirror, and the transmissive white light source constitute a front imaging unit for acquiring an image of the micro-hole array processed by the femtosecond laser; and wherein the phase-type spatial light modulator, the first plano-convex lens, the second plano-convex lens, and the processing objective lens together constitute a 4F system, and the 4F system is configured to prevent diffraction effect from happening in a light field modulated by the phase-type spatial light modulator before reaching the processing objective lens, wherein a focal length of the first plano-convex lens is same as that of the second plano-convex lens, a distance between the first plano-convex lens and the second plano-convex lens is twice as long as the focal length, a distance between the first plano-convex lens and a liquid crystal screen of the phase-type spatial light modulator is equal to the focal length, and a distance between the second plano-convex lens and the processing objective lens is equal to the focal length.

2 . The femtosecond laser system for processing the micro-hole array according to claim 1 , wherein the femtosecond laser is a titanium sapphire femtosecond laser.

3 . The femtosecond laser system for processing the micro-hole array according to claim 1 , wherein the femtosecond laser has a pulse repetition frequency of 10 to 1000 Hz.

4 . The femtosecond laser system for processing the micro-hole array according to claim 1 , wherein the femtosecond laser has a single pulse energy of 20 to 200 μJ.

5 . The femtosecond laser system for processing the micro-hole array according to claim 1 , wherein the femtosecond laser has a beam waist diameter before focusing of 4 to 12 mm.

6 . The femtosecond laser system for processing the micro-hole array according to claim 1 , wherein the femtosecond laser has a center wavelength of 800 nm and a pulse width of 35 fs.

7 . The femtosecond laser system for processing the micro-hole array according to claim 1 , wherein the camera is an industrial-grade CCD.

Assignees

• Univ Tsinghua

Inventors

• Jiang Lan
• Yan Jianfeng
• Li Jiaqun

Classifications

• B23K26/06 Primary

  Shaping the laser beam, e.g. by masks or multi-focusing · CPC title

• B23K26/382

  by boring · CPC title

• B23K26/384

  of specially shaped holes · CPC title

• B23K26/0861

  in at least three axial directions · CPC title

• B23K26/0648

  comprising lenses · CPC title