Parallel laser manufacturing system and method

Patent metadata

Field	Value
Publication number	US-2016199935-A1
Application number	US-201514594871-A
Country	US
Kind code	A1
Filing date	Jan 12, 2015
Priority date	Jan 12, 2015
Publication date	Jul 14, 2016
Grant date	—

Abstract

A laser manufacturing system capable of fabricating 3-D resolved 2-D patterns. The system includes a pulse laser source generating a laser beam; a reflectance mirror arranged in the propagation path of the laser to reflect the laser, the mirror being controllable to adjust an emergent angle of the laser; a deformable dispersion unit located in the laser receiving path from the reflectance mirror and having an array of micromirrors controllable in response to the adjusted emergent angle to form required laser patterns from the reflected laser, the laser patterns having spatially separated optical spectral components with multiple propagation angles; and one or more focusing optical components positioned in the propagation path of the separated optical spectral components produced by the deformable dispersion unit; the focusing components recombine the optical spectral components at fabrication targets with patterns defined by the deformable dispersion unit. The laser pulse duration is shortest on or inside the fabrication target along the laser propagation path.

First claim

What is claimed is:

1 . A laser manufacturing system, comprising:
a laser source generating a pulsed laser beam; a reflectance mirror arranged in a propagation path of the laser to reflect the laser, the mirror being controllable to adjust an emergent angle of the laser; a deformable dispersion unit located in a laser receiving path from the reflectance mirror and having an array of micromirrors controllable in response to the adjusted emergent angle to form required laser patterns from the reflected laser, the laser patterns having spatially separated optical spectral components with a plurality of propagation angles; and one or more focusing units positioned in a propagation path of the separated optical spectral components produced by the deformable dispersion unit, the focusing units recombine the optical spectral components on or inside fabrication targets, where a laser pulse duration of the beam is shortest.

2 . The system of claim 1 , wherein the focusing units comprise:
a first focusing unit positioned in the propagation path of the separated optical spectral components and having a focal length that is able to collimate the optical spectral components into a parallel laser beam; and a second focusing unit optically coupled to the first focusing unit and having a focal length to focus the laser to pattern one or more samples located on a focal plane of the second focusing unit.

3 . The system of claim 1 , wherein the deformable dispersion unit is configured to function as at least one selected from a group consisting of:
a photomask with grating structures, a shaped transmission or reflectance grating, a digital micromirror device (DMD); a microelectromechanical system (MEMS) mirror array.

4 . The system of claim 1 , wherein each of the micromirrors has at least one pixel, and laser intensity in each pixel is controllable by changing a switching (on-off) rate of each pixel, allowing more complex beam intensity profile to be engineered.

5 . The system of claim 4 , wherein a switching speed of each pixel in individual micromirror in the deformable dispersion unit is controllable to arbitrarily adjust an intensity profile across laser patterns formed by the deformable dispersion unit.

6 . The system of claim 1 , further comprising:
a GVD controller having a dispersive optical unit or array electrically configurable to spatially adjust a dispersion level for said spatially separated optical spectral components, so as to control a location of a focal plane where all optical spectral components meet along their optical axis.

7 . The system of claim 6 , wherein the dispersive optical unit adjusts a relative optical path difference and a phase of the laser beam to adjust said dispersion level.

8 . The system of claim 1 , wherein, the focusing units are configured with a focal length re-configurable to make a duration of laser pulses vary along its propagation direction after the focal units to achieve a highest peak power at different focal planes.

9 . The system of claim 2 , wherein, the second focusing unit has a focus re-configurable to scan the required patterns formed by the deformable dispersion unit along its propagation direction after the second focusing unit to achieve a highest peak power only at the focal planes.

10 . The system of claim 2 , wherein said focusing units comprise one or more selected from a group consisting of a focusing unit, or a concave reflectance mirror, or focus tunable focusing unit, or an objective, or a combination thereof such that the dispersed optical spectral components are recombined at said focal plane.

11 . The system of claim 2 , further comprising:
A XYZ stage holding the fabrication targets, the fabrication targets being located at the focal plane.

12 . The system of claim 1 , further comprising a microscopic imaging system positioned in the propagation path of beam for observing a laser machining process in real time.

13 . The system of claim 1 , wherein the generated laser beam comprises two perpendicular polarization components, and the system further comprises:
a half-wave plate positioned in a laser receiving orientation from the laser source and shifting phases between two perpendicular polarization components so as to retard one polarization of the two perpendicular polarization components by half a wavelength of the laser.

14 . The system of claim 13 , further comprising:
a polarization beam splitter located in a propagation path of the laser received from the half-wave plate, wherein the polarization beam splitter splits the laser received from the half-wave plate into two laser beams, one is reflected to the reflectance mirror, and the other one is transmitted for monitoring a quality of the generated beam.

15 . The system of claim 14 , further comprising:
a shutter positioned in a propagation path of reflected beam for switching on/off the laser propagation path.

16 . The system of claim 1 , further comprising a DBP System positioned between the laser source and the reflectance mirror to shape pulses of the generated pulsed laser beam.

17 . The system of claim 16 , wherein the DBP System comprises:
a beam diameter regulator located in a beam receiving path and configured to adjust a diameter of the beam received in the beam receiving path; a first dispersion unit located in the beam receiving path and separating the spectral components from the adjusted laser to make the separated spectral components transmit out with different emergent angles; a first focusing unit located in a beam path from the first dispersion unit and configured to collimate the spectral components of the beam with different emergent angles into a parallel laser beam and to convert the separated spectral components with different emergent angles (angular dispersion) to a plurality of spatially dispersed spectral components at a back focal plane of the first focusing unit; a modulating unit positioned on the back focal plane to form arbitrary patterns of the laser from the spatially and spectrally dispersed optical components; and a second focusing unit located in the beam path and is used to combine different spectral components back to a second dispersion unit positioned at a focal plane of the second focusing unit, wherein the second dispersion unit recombines all the spectral components into a single collimated beam, obtaining a re-shaped output pulse of the beam.

18 . The system of claim 16 , wherein the DBP System comprises:
a beam diameter control unit located in a beam receiving path and configured to adjust a diameter of the beam received in the beam path; a first focusing unit optically coupled to the control unit to focus the laser beam with the adjusted diameter; a first dispersion unit having a micro- or nano-structure to separate the laser beam to be different spectral components in a first direction; a second dispersion unit having a micro- or nano-structure to separate the different spectral components in a second direction so as to achieve two-dimensional pulse shaping of the laser beam; a second focusing unit optically coupled to the second dispersion unit to collimate the dispersed laser beam; and a modulation unit optically coupled to the second focusing unit to modulate different spectral components of the laser pulse.

19 . A laser manufacturing method, comprising
generating a pulsed laser beam; adjusting an emergent angle of the pulsed laser beam; forming required laser patterns from the pulsed laser beam in resp

Assignees

• Univ Hong Kong Chinese

Inventors

• Chen Shih-Chi
• Zhang Dapeng
• Gu Chenglin
• Jiang Jun
• Yeung Yam

Classifications

• G02B26/0833

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• B23K26/0622

  by shaping pulses · CPC title

• B23K26/066

  by using masks · CPC title

• G02B27/285

  comprising arrays of elements, e.g. microprisms · CPC title

• B23K26/0054 Primary

  Operations & Transport · mapped topic