Green welding laser

1. A harmonic laser system, comprising:

an oscillator cavity having a first end mirror and a harmonic separator mirror,

an active medium positioned in the oscillator cavity;

an electro-optic pump device comprising a pulsed power source for optically pumping the active medium to produce a first optical beam at a fundamental wavelength and having a peak power of 1-10 kW without using a Q-switch device;

a non-linear optical crystal positioned in the oscillator cavity for generating a second optical beam, which is suitable for laser welding, at a harmonic wavelength of said first optical beam in response to converging the first optical beam onto the non-linear optical crystal, the harmonic wavelength being a green wavelength; and

a focusing lens for converging the first optical beam to the non-linear optical crystal, wherein said harmonic separator mirror outputs said second optical beam and reflects said first optical beam.

2. The harmonic laser system of claim 1 , wherein said second optical beam welds a first workpiece to a second workpiece.

3. The harmonic laser system of claim 1 , wherein said second optical beam generates heat in a workpiece for changing material properties of the workpiece, reshaping the workpiece, or removing material from the workpiece.

4. The harmonic laser system of claim 1 , wherein the focusing lens converges the first optical beam onto a surface of the non-linear optical crystal.

5. The harmonic laser system of claim 1 , wherein a focal length of the focus lens is between about 100 mm and 150 mm.

6. The harmonic laser system of claim 1 , wherein the first and second optical beams comprise a pulsed laser.

7. The harmonic laser system of claim 6 , wherein pulse width for the pulsed laser is greater than 100 microseconds.

8. The harmonic laser system of claim 1 , wherein the non-linear optical crystal is selected from a group consisting of a doubling, tripling and quadrupling non-linear crystals.

9. The harmonic laser system of claim 1 , wherein the non-linear optical crystal comprises a plurality of non-linear crystals arrayed in series so as to increase the conversion efficiency of the second optical beam by generating high order (N< 3 ) harmonics.

10. The harmonic laser system of claim 1 , wherein the active medium is selected from a group consisting of a gaseous medium and a laser crystal.

11. The harmonic laser system of claim 1 , wherein the electro-optic pump device is a laser diode.

12. The harmonic laser system of claim 1 , wherein the active medium and the non-linear optical crystal are co-linear with one another.

13. The harmonic laser system of claim 1 , wherein the oscillator cavity comprises a folded oscillator cavity wherein the first optical beam and the second optical beam are at an angle with one another, and the oscillator cavity further comprises a second end mirror co-linear with the non-linear optical crystal for reflecting both the first and second optical beams towards the non-linear optical crystal.

14. The harmonic laser system of claim 1 , wherein the fundamental wavelength is 1064 nm and the harmonic wavelength is 532 nm.

15. A method of generating a second optical beam having a harmonic wavelength of a wavelength of a first optical beam having the fundamental wavelength and having a peak power of 1-10 KW, without using a Q-switch device, by optically pumping an active medium using a pulsed power source;

converging the first optical beams to a harmonic separator mirror that passes through the second optical beam and reflects the first optical beam.

16. The method of claim 15 , wherein said converging comprises focusing the first optical beam onto a surface of the non-linear optical crystal.

17. The method of claim 15 , wherein the first and second optical beams are normally incident upon the harmonic separator mirror.

18. The method of claim 15 , wherein the first and second optical beams are incident upon the harmonic separator mirror at a non-normal angle and at an angle with each other.

19. The method of claim 15 , further comprising welding a first workpiece to a second workpiece using the second optical beam.

20. The method of claim 15 , further comprising generating heat using the second optical beam in a workpiece to change material properties of the workpiece, reshape the workpiece, or remove material from the workpiece.

21. The harmonic laser system of claim 1 , wherein the electro-optic pump device is not in an optical path of the first optical beam or the second optical beam.

22. A harmonic laser system, comprising:

an oscillator cavity having a first end mirror and a harmonic separator mirror;

an active medium positioned in the oscillator cavity;

a flash lamp for optically pumping the active medium to produce a first optical beam at a fundamental wavelength and having a peak power of 1-10 kW without using a Q-switch device;

a non linear optical crystal positioned in the oscillator cavity for generating a second optical beam, which is suitable for laser welding, at a harmonic wavelength of said first optical beam in response to converging the first optical beam onto the non-linear optical crystal; and

a focusing lens for converging the first optical beam onto the non-linear optical crystal, wherein said harmonic separator mirror outputs said second optical beam and reflects said first optical beam, and

wherein the harmonic wavelength is a green wavelength.