Green diode laser

• US 20050163176A1
• Filed: 01/26/2004
• Published: 07/28/2005
• Est. Priority Date: 01/26/2004
• Status: Active Grant

• Current Assignee: Shanghai Uniwave Technology Company Limited
• Original Assignee: Shanghai Uniwave Technology Company Limited
• Inventors: Xu, Zheng-Hua, Zhang, Wen-Zhao, Zheng, Xian-Wen, Xu, Wen-Hu, Zhang, Shao-Feng, Chen, Yan-Ping, You, Li-Ning
• Granted Patent: US 7,003,006 B2
• Time in Patent Office: Days
• US Class Current: 372/36
• CPC Class Codes: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• CPC Class Codes: H01S 3/0078 Frequency filtering
• CPC Class Codes: H01S 3/025 of solid state lasers, e.g. housings or mountings
• CPC Class Codes: H01S 3/042 for solid state lasers H01S3/0401 takes precedence
• CPC Class Codes: H01S 3/0604 in the form of a plate or disc
• CPC Class Codes: H01S 3/0627 the resonator being monolithic, e.g. microlaser
• 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 3/109 Frequency multiplication, e.g. harmonic generation
• CPC Class Codes: H01S 3/1305 Feedback control systems
• CPC Class Codes: H01S 3/1312 by controlling the optical pumping
• CPC Class Codes: H01S 3/1611 neodymium
• CPC Class Codes: H01S 3/1643 YAG
• CPC Class Codes: H01S 5/02208 characterised by the shape of the housings
• CPC Class Codes: H01S 5/02255 using beam deflecting elements
• CPC Class Codes: H01S 5/024 Arrangements for thermal management

Abstract

A green diode laser includes a tubular laser casing, a heat sink sealedly mounted at the laser casing, a semiconductor chip supported by the heat sink, an optical resonant cavity supported within the laser casing, including a lasing medium and an intracavity frequency doubler, an IR blocking filter inclinedly and seadedly mounted at the laser casing to optically communicate with an output facet, and a photodiode supported within the laser casing at a position that when the laser beam exits the output facet, the IR blocking filter reflects a portion of the laser beam towards the photodiode such that the photodiode is adapted for detecting the laser beam from the IR blocking filter as a feedback for controlling a power output of the green laser chip.

Claims

1-21. -21. (canceled)

22. A green Diode laser, comprising:

a tubular laser casing having a first opening end and a second opening end;

a heat sink sealedly mounted at said first opening end of said laser casing;

a semiconductor chip supported by said heat sink for emitting a pumping radiation;

an optical resonant cavity supported within said laser casing, including a lasing medium to optically communicate with said semiconductor chip for a light amplification of fundamental frequency, and an intracavity frequency doubler to optically communicate with said lasing medium for frequency doubling of said fundamental frequency, wherein an input facet is formed at said lasing medium for said pumping radiation entering thereinto, an output facet is formed at said intracavity frequency doubler for said frequency-double beam exiting therefrom;

an IR blocking filter inclinedly and sealedly mounted at said second opening end of said laser casing to optically communicate with said output facet of said intracavity frequency doubler; and

a photodiode supported by said heat sink at a position that when said frequency-double beam exits said output facet, said IR blocking filter reflects a portion of said frequency-double beam towards said photodiode such that said photodiode is adapted for detecting said frequency-double beam from said IR blocking filter as a feedback for controlling a power output of said optical resonant cavity.

23. The green diode laser, as recited in claim 22, wherein said lasing medium and said intracavity frequency doubler are combined together, said input facet of said lasing medium is coated with a coating having a high transmissivity at a wavelength of 808 nm and a high reflectance at wavelength of 1064 nm and 532 nm while said output facet of said intracavity frequency doubler is coated with a coating having a high transmissivity at a wavelength of 532 nm and a high reflectance at a wavelength of 1064 nm.

24. The green diode laser, as recited in claim 23, wherein a filter having a high transmissivity at a wavelength of 532 nm and a high reflectance at wavelength of 1064 nm and 808 nm is covered on the light detecting surface of the photodiode.

25. The green diode laser, as recited in claim 24, wherein said intracavity frequency doubler is KTP.

26. The green diode laser, as recited in claim 25, wherein said lasing medium is Nd:

YVO₄.

27. The green diode laser, as recited in claim 26, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation.

28. The green diode laser, as recited in claim 25, wherein said lasing medium is Nd:

GdVO₄.

29. The green diode laser, as recited in claim 28, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation.

30. The green diode laser, as recited in claim 23, wherein a light detecting surface of said photodiode is coated with a coating having a high transmissivity at a wavelength of 532 nm and a high reflectance at wavelength of 1064 nm and 808 nm.

31. The green diode laser, as recited in claim 30, wherein said intracavity frequency doubler is KTP.

32. The green diode laser, as recited in claim 31, wherein said lasing medium is Nd:

YVO₄.

33. The green diode laser, as recited in claim 32, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation.

34. The green diode laser, as recited in claim 31, wherein said lasing medium is Nd:

GdVO₄.

35. The green diode laser, as recited in claim 34, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation.

36. The green diode laser, as recited in claim 22, wherein said lasing medium and said intracavity frequency doubler are spaced with each other, said input facet of said lasing medium is coated with a coating having a high transmissivity at a wavelength of 808 nm and a high reflectance at wavelength of 1064 nm and 532 nm while a facet of said lasing medium opposite to said input facet is coated with a coating having a high transmissivity at wavelength of 1064 nm and 532 nm, said output facet of said intracavity frequency doubler is coated with a coating having a high transmissivity at a wavelength of 532 nm and a high reflectance at a wavelength of 1064 nm while a facet of said intracavity frequency doubler opposite to said output facet is coated with a coating having a high transmissivity at wavelength of 1064 nm and 532 nm.

37. The green diode laser, as recited in claim 36, wherein a filter having a high transmissivity at a wavelength of 532 nm and a high reflectance at wavelength of 1064 nm and 808 nm is covered on the light detecting surface of the photodiode.

38. The green diode laser, as recited in claim 37, wherein said intracavity frequency doubler is KTP.

39. The green diode laser, as recited in claim 38, wherein said lasing medium is Nd:

YVO₄.

40. The green diode laser, as recited in claim 39, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation.

41. The green diode laser, as recited in claim 38, wherein said lasing medium is Nd:

GdVO₄.

42. The green diode laser, as recited in claim 41, further comprising a focusing device mounted between said semiconductor chip and said input facet of said lasing medium for focusing of said pumping radiation.

43. The green diode laser, as recited in claim 22, further comprising a Q-switch crystal supported within said laser casing between said lasing medium and said intracavity frequency doubler for converting said laser beam into a pulsed one.

44. The green diode laser, as recited in claim 22, further comprising a single mode device supported within said laser casing between said lasing medium and said intracavity frequency doubler for converting said laser into a single longitude mode laser.