Coherent light generators – Particular active media
Reexamination Certificate
2000-07-13
2003-11-18
Ip, Paul (Department: 2828)
Coherent light generators
Particular active media
C372S041000
Reexamination Certificate
active
06650670
ABSTRACT:
BACKGROUND
This invention relates to polycrystalline ceramic composite lasers. Ikesue et al. disclose “Fabrication . . . of Polycrystalline Nd:YAG Ceramics for . . . Lasers” in J. Am. Ceram. Soc., vol. 78(4), p. 1033-40 (1995). Greskovich et al. disclose in U.S. Pat. No. 3897358 a method of pressing and sintering polycrystalline laser material. Taira, Ikesue and Yoshida have disclosed efficient laser operation of Nd:YAG polycrystalline ceramic microchips in “Performance . . . Nd-doped YAG Ceramic Microchip Lasers”, in CLEO'99 Technical Digest, p. 136 (May /1999). It is taught that this new polycrystalline ceramic form allows higher doping, which provides 10 times higher absorption of pump energy, and it is reported that the maximum output power is four times higher than that of Nd:YAG single crystal.
However, due to higher absorption coefficient of these highly doped polycrystalline ceramics, experimental laser specimens of the prior art generate excessive heat that degrades the various coatings required to form optical laser cavities. This has resulted in the premature failure of the laser cavity. Therefore, there is a need to produce a polycrystalline laser that can efficiently dissipate the additional heat generated therein during laser operation to allow long term, reliable laser operation.
SUMMARY
An object of the present invention is to provide a polycrystalline laser having a means of dissipating heat efficiently, so that the optical coatings maintain their integrity during long-term laser use. Another object of the present invention is to provide various novel, unique embodiments of end-pumped and side-pumped polycrystalline lasers which can survive long term use. Another object of the present invention is to provide a polycrystalline laser that accomplishes the above objects at low energy consumption and low manufacturing cost.
These and other objects of the present invention are achieved in the present invention by a doped polycrystalline laser ceramic being contiguous with an undoped or pure, polycrystalline ceramic. The pure, undoped ceramic portion functions to efficiently dissipate the heat generated within the doped laser ceramic during laser operation. Low energy consumption is provided by the higher absorption of the doped polycrystalline, because of the higher allowed dopant concentrations. Low manufacturing cost is achieved by creating the laser gain material and the heat sink out of the same ceramic, thus minimizing the number of different materials that must be assembled.
REFERENCES:
patent: 3897358 (1975-07-01), Greskovich et al.
patent: 4217558 (1980-08-01), Aprahamian et al.
patent: 4953166 (1990-08-01), Mooradian
patent: 4965803 (1990-10-01), Esterowitz et al.
patent: 5008890 (1991-04-01), McFarlane
patent: 5289482 (1994-02-01), Esterowitz et al.
patent: 5295146 (1994-03-01), Gavrilovic et al.
patent: 5327444 (1994-07-01), Mooradian
patent: 5388114 (1995-02-01), Zarrabi et al.
patent: 5491708 (1996-02-01), Malone et al.
patent: 5508235 (1996-04-01), Marker
patent: 5541948 (1996-07-01), Krupke et al.
patent: 5574740 (1996-11-01), Hargis et al.
patent: 5677921 (1997-10-01), Schaffers et al.
patent: 5751751 (1998-05-01), Hargis et al.
patent: 5805626 (1998-09-01), Komatsu et al.
patent: 5914975 (1999-06-01), Kuwano
patent: 6246711 (2001-06-01), Stultz et al.
patent: 6370172 (2002-04-01), Bowman
patent: 6466600 (2002-10-01), Von Borstel
T. Taira et al “Performance of Highly Nd3+—Doped YAG Ceramic Microchip Laser” CLEO'99 Technical Digest p136 (May 1999).
kresue et al. Fabrication and Optical Properties of High-Performance Polycrystalline Nd: YAG Ceramics for Solid-State Lasers J. AM. Cerma. Soc. 78 p1033 (1995).
Ip Paul
Nguyen Tuan
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