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JP-7855568-B2 - Applications, methods, and systems for material processing using visible Raman lasers

JP7855568B2JP 7855568 B2JP7855568 B2JP 7855568B2JP-7855568-B2

Inventors

  • ゼディカー， マーク， エス．

Assignees

  • ヌブル インク

Dates

Publication Date
20260508
Application Date
20231227
Priority Date
20140827

Claims (6)

  1. A laser processing apparatus for fabricating parts, a. A laser having a pump laser diode and for providing a functional laser beam along a beam path, wherein the functional laser beam has a wavelength in the range of 405 to 450 nm, an M² of less than 2, and a power in the range of 1 to 2.25 kW . b. A platform having a target area for placing the target material, c. A laser beam delivery apparatus having a beam shaping optical element for providing a functional laser beam and forming a functional laser beam spot, d. A motor and positioning device mechanically connected to the base, the laser beam delivery device, or both, and configured to provide relative movement between the laser beam delivery device and the base, e. A control system having a processor and a memory device, capable of performing a laser process plan by a predetermined arrangement of the functional laser beam spots on the target area, A laser processing apparatus equipped with the following features.
  2. The laser processing apparatus according to claim 1, wherein the functional laser beam has a beam parameter product of 0.3 to 0.6 mm-mrad.
  3. The laser processing apparatus according to claim 1 or 2, wherein the functional laser beam spot has a cross-section of 1 to 10 μm.
  4. The laser processing apparatus according to claim 1 or 2, wherein the functional laser beam spot has a cross-section of 1 to 2 μm.
  5. The laser processing apparatus according to any one of claims 1 to 4, wherein the functional laser beam has a beam waist of 10 μm.
  6. The laser processing apparatus according to any one of claims 1 to 5, wherein the functional laser beam is a continuous beam.

Description

[0001] This application (i) claims the filing date benefit under 35 United States Code, Section 119(e)(1) with respect to the filing date of U.S. Provisional Patent Application No. 62/042,785, dated August 27, 2014, and (ii) claims the filing date benefit under 35 United States Code, Section 119(e)(1) with respect to the filing date of U.S. Provisional Patent Application No. 62/193,047, dated July 15, 2015, with the entire disclosures of each of these provisional patent applications incorporated herein by reference. [0002] The present invention relates to a laser that generates a laser beam in the range of 300 nm to 700 nm, and the laser beam includes a higher power laser beam having excellent beam quality in these wavelengths. The present invention further relates to a laser manufacturing process, a laser manufacturing system, and a laser manufacturing device, and more particularly to a laser-based manufacturing process using the novel laser beam of the novel laser of the present invention. [0003] Prior to the present invention, laser beams in the 300 nm–700 nm range were typically obtained from laser sources using frequency doubling of near-infrared or infrared lasers. To date, generally and especially for commercially viable systems, it is considered that the technology has not been able to scale these types of lasers to produce higher-power lasers, for example, lasers greater than 500 W (0.5 kW), and especially lasers greater than 1 kW. Consequently, it is considered that the technology has not been able to scale these lasers to obtain high-power lasers with high beam quality in the 300 nm–700 nm range. This inability to obtain high-power lasers in these wavelength ranges is generally considered to be limited, technically, by the ability of nonlinear crystals to handle the thermal load and fluence levels required at high power levels, among other things. As a consequence, the highest-power, high-beam-quality lasers available by frequency doubling are currently considered to be limited to pulses of about 400 W (0.4 kW). Pulsing is necessary to control the thermal load on the crystal. It is believed that commercially viable or useful lasers with higher power, for example, 1 kW or more, in the 300 nm–700 nm range and higher beam quality, for example, M² to 1, had not been available prior to the present invention. [0004] Prior to the embodiment of the present invention, it is thought that there were broadly four types of blue lasers. Blue lasers are lasers having wavelengths in the range of approximately 400 nm to 505 nm, typically 405 nm to 495 nm. These blue lasers are (i) He:Cd type, (ii) Ar-ion type, (iii) diode laser direct and frequency doubling type, (iv) solid-state parametric oscillator and frequency doubling type, and (v) fiber laser doubling type and frequency shift fiber laser doubling type. (i) He:Cd type lasers are single-mode, but their power is limited to several hundred milliwatts, for example, 0.0001 kW. Although He:Cd type lasers are typically single transverse-mode, their low efficiency (<0.025%) makes it extremely difficult to scale them to high power levels, and therefore they are not suitable for high-power material processing applications. (ii) Ar-ion lasers are very inefficient and, as a result, are limited to relatively low power, i.e., less than approximately 0.005 kW for multi-line operation. At these low powers, these lasers are single transverse modes with multi-wavelength operation. The lifetime of these systems is typically <5,000 hours, which is relatively short for most industrial applications. (iii) Blue diode lasers have become available in recent years. However, they have low power, typically less than 0.0025 kW, and poor beam quality, for example, M² > 5 on the slow axis and M² ~ 1 on the fast axis. These devices now have a lifetime on the order of 20,000 hours and are suitable for many industrial and commercial laser applications. When attempting to scale these devices to 200 watts or more, beam quality deteriorates with increasing power. For example, M² > 50 at 200 watts. (iv) Frequency-doubling blue laser sources are typically limited to an output power of around 0.50 kW. Methods for creating blue light would involve either frequency doubling a light source in the 800 nm–900 nm range or generating a third frequency using sum-frequency mixing of two different wavelengths. Both techniques require the use of nonlinear doubling crystals such as lithium niobate or KTP. These crystals are relatively short, and as a consequence, they require high peak power levels to achieve efficient conversion. When operating in CW mode, thermal and charge transfer problems may cause rapid crystal degradation and the resulting decrease in laser output power. (v) Fiber lasers that are frequency-shifted and then frequency-dualized to blue require the use of nonlinear dual-duplication crystals such as lithium niobate or KTP. These crystals are relatively short, and as a result, they require