Method and system for stable and tunable high power pulsed laser system

• US 8,964,801 B2
• Filed: 06/08/2010
• Issued: 02/24/2015
• Est. Priority Date: 06/11/2009
• Status: Expired due to Fees

• Current Assignee: Electro Scientific Industries Incorporated (MKS Instruments Incorporated)
• Original Assignee: ESI-Pyrophotonics Lasers, Inc. (MKS Instruments Incorporated)
• Inventors: Reid, Benoit, Panarello, Tullio, Caplette, Stephane
• Primary Examiner(s): Zhang, Yuanda
• Application Number:
  US12/796,193
• Publication Number:
  US 20110142084A1
• Time in Patent Office: 1,722 Days
• Field of Search: 372/6, 372/20
• US Class Current: 372/20
• CPC Class Codes: B23K 2101/10 Pipe-lines
• CPC Class Codes: B23K 2101/12 Vessels
• CPC Class Codes: B23K 2101/34 Coated articles , e.g. plated or painted; Surface treated articles
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 2103/10 Aluminium or alloys thereof
• CPC Class Codes: B23K 2103/12 Copper or alloys thereof
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 2103/42 Plastics B23K2103/16 takes precedence
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 2103/54 Glass
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/142 for the removal of by-products
• CPC Class Codes: B23K 26/16 Removal of by-products, e.g. particles or vapours produced during treatment of a workpiece by a fluid stream B23K26/142
• CPC Class Codes: B23K 26/382 by boring
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: C03C 2218/328 Partly or completely removing a coating
• CPC Class Codes: H01S 2301/02 ASE (amplified spontaneous emission), noise; Reduction thereof
• CPC Class Codes: H01S 2301/03 Suppression of nonlinear conversion, e.g. specific design to suppress for example stimulated brillouin scattering [SBS], mainly in optical fibres in combination with multimode pumping
• CPC Class Codes: H01S 3/0092 Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity nonlinear frequency conversion per se G02F1/35
• CPC Class Codes: H01S 3/06754 : Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/06758 : Tandem amplifiers
• CPC Class Codes: H01S 3/09415 : the pumping beam being parallel to the lasing mode of the pumped medium, e.g. end-pumping
• CPC Class Codes: H01S 3/1001 : by controlling the optical pumping
• CPC Class Codes: H01S 3/10015 : by monitoring or controlling, e.g. attenuating, the input signal
• CPC Class Codes: H01S 3/1618 : ytterbium
• CPC Class Codes: H01S 3/2375 : Hybrid lasers H01S3/07 takes precedence
• CPC Class Codes: H01S 5/005 : Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/0078 : for frequency filtering
• CPC Class Codes: H01S 5/06216 : Pulse modulation or generation
• CPC Class Codes: H01S 5/146 : using a fiber as external cavity
• CPC Class Codes: H01S 5/4006 : Injection locking
• CPC Class Codes: H01S 5/5018 : using two or more amplifiers or multiple passes through the same amplifier
• CPC Class Codes: H05K 3/0038 : combined with laser drilling through a metal layer

Abstract

A laser system includes an injection laser source having an output and operable to provide a laser output characterized by a first wavelength, a first linewidth, an output power. The laser system also includes a tunable pulsed source characterized by a gain bandwidth. The tunable pulsed source is operable to provide an output signal having an average power. The output signal includes a plurality of optical pulses. Each of the plurality of optical pulses is characterized by a second wavelength, a second linewidth, and a peak power. The laser system further includes an optical combiner having a first port coupled to the output of the injection laser source, a second port coupled to the tunable pulsed source, and a third port.

Claims

1. A method for providing a plurality of signal pulses, the method comprising:

providing a stabilizing optical radiation signal characterized by a first center wavelength, a first spectral linewidth, and an ooutput power;

coupling the optical radiation signal into a first port of an optical combiner;

transmitting the optical radiation signal from the first port to a second port of the optical combiner;

coupling the optical radiation signal from the second port into a tunable pulsed laser source comprising a semiconductor laser;

driving the tunable pulsed laser with drive signal to produce a plurality of signal pulses having temporal pulse shape, and including applying the drive signal to the semiconductor laser to adjust the temporal pulse shape in real time from pulse to pulse;

injection locking the laser to stabilize the spectral linewidth of the plurality of signal pulses;

coupling the plurality of signal pulses into the second port;

transmitting the plurality of signal pulses from the second port to a third port of the optical combiner; and

outputting the plurality of signal pulses from the third port;

coupling the plurality of signal pulses into an input end of an optical amplifier;

amplifying the plurality of signal pulses; and

outputting the plurality of amplified signal pulses at an output end of the optical amplifier.

2. The method of claim 1 wherein said amplifying includes using an optical amplifier comprising a pump source optically coupled to an optically active fiber.

3. The method of claim 1 where a peak power of pulses in the plurality of amplified, signal pulses is greater than 1 kW.

4. The method of claim 1, including changing the drive signal between consecutive optical pulses in the plurality of optical pulses.

5. The method of claim 1, including applying control signal to change the first center wavelength of the optical radiation signal.

6. The method of claim 1, including producing a feedback signal, and changing the drive signal in response to the feedback signal.

7. A laser system comprising:

an injection laser source having an output and operable to provide a laser output characterized by a first wavelength, a first linewigth, an output power;

a tunable pulsed source, comprising a semiconductor laser, characterized by gain bandwidth, the tunable source being operable to provide an output signal having an average power, the output signal comprising a plurality of optical pulses, each of the plurality of optical pulses being characterized by second wavelength, a second linewidth, and a peak power; and

an optical combiner having a first port couples to the output of the injection laser source, a second port coupled to the tunable pulsed source from which the tunable pulsed source receives the laser output of the injection laser source, and a third port; and

a controller connected with the tunable pulsed source which applies drive signal to the semiconductor laser to control temporal pulse shape of pulses in the plurality of optical pulses, and is configured to change the drive signal to the semiconductor laser to adjust the temporal pulse shapes in the plurality of optical pulses in real time, and wherein the second linewidth is stabilized by laser output of the injection laser source.

8. The laser system of claim 7 wherein the optical combiner comprises a three-port optical circulator.

9. The laser system of claim 7 wherein the injection laser source comprises a continuous wave semiconductor laser.

10. The laser system of claim 9 wherein the continuous wave semiconductor laser comprises a fiber Bragg grating stabilized semiconductor laser.

11. The laser system of claim 7 wherein the injection laser source comprises a pulsed semiconductor laser having a pulse width substantially longer than a pulse width of each of plurality of optical pulses.

12. The laser system of claim 7 wherein a front facet reflectivity of the semiconductor laser is less than 1%.

13. The laser system of claim 12 wherein the front facet reflectivity is less than 0.01%.

14. The laser system of claim 7 wherein the first center wavelength is within the gain bandwidth.

15. The laser system of claim 7 wherein the second spectral linewidth is approximately equal to the first linewidth.

16. The laser system of claim 7 wherein the second center wavelength is approximately equal to the first wavelength.

17. The laser system of claim 7 wherein the optical amplifier comprises an optically active fiber and a pump source optically coupled to the optically active fiber.

18. The laser of claim 7, wherein the controller is configured to change the drive signal between consecutive optical pulses in the plurality of optical pulses.

19. The laser system of claim 7, wherein the controller is connected with the injection laser source, and configured apply control signal to change the first wavelength of the laser output.

20. The laser system of claim 7, including a detector producing a feedback signal, and wherein the controller is configured to change the drive signal in response to the feedback signal.