Compositions – Light transmission modifying compositions – Inorganic crystalline solid
Reexamination Certificate
1995-07-17
2001-10-02
Bos, Steven (Department: 1754)
Compositions
Light transmission modifying compositions
Inorganic crystalline solid
C423S277000, C117S013000, C117S074000, C117S944000, C359S328000, C359S330000, C372S021000, C372S022000, C372S039000, C372S041000
Reexamination Certificate
active
06296784
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cesium-lithium-borate crystal and crystals with substituted chemical compositions thereof. More particularly, the present invention relates to a cesium-lithium-borate crystal and crystals with substituted chemical compositions thereof which are used as frequency converting nonlinear optical crystals in laser oscillators and optical parametric oscillators used in blue and ultraviolet lithography, laser microprocessing, scientific and industrial measurement and laser nuclear fusion, a method for manufacturing same, and an optical apparatus using same.
2. Prior Art and Problems
Laser oscillators used in ultraviolet lithography, laser microprocessing, scientific and industrial measurement and laser nuclear fusion must generate stable blue and ultraviolet rays efficiently. One of the methods to achieve the above object which is attracting the general attention to day is the method to efficiently obtain blue and ultraviolet rays by frequency conversion of a light source using nonlinear optical crystals.
A pulse YAG laser oscillator, a type of laser oscillators, for example, uses nonlinear optical crystals to convert frequency of a light source to generate the third (wavelength: 355 nm) or the fourth (wavelength: 266 nm) harmonics of the pulse YAG laser.
Many contrivances on the frequency converting none linear optical crystals which are indispensable for generating ultraviolet rays have been announced. For example, beta barium methaborate (&bgr;-BaB
2
O
4
), lithium triborate (LiB
3
O
5
), cesium triborate (CsB
3
O
5
) and other borate crystals are known. These frequency converting nonlinear optical crystals for generating blue and ultraviolet rays will pass wavelengths of 200 nm and below, and have a large nonlinear optical coefficient.
It is very difficult, however, to grow crystals of &bgr;-BaB
2
O
4
, one of such frequency converting nonlinear optinal crystals, because of the tendency of causing phase transition in the production process. Further, angular allowance is very tight, and thus this particular substance has a very low level of generality.
Furthermore, for LiB
3
O
5
other frequency converting nonlinear optical crystal, the growth time is very long as a result of flux growth in the production process, and this crystal is only good for phase matching for rays down to about 555 nm wavelengths for second harmonic generation. This crystal is used, for example, for generation of the third harmonic (wavelength: 355 nm) of Nd-YAG lasers, but cannot be used for generating the fourth harmonic (wavelength: 266 nm)
SUMMARY OF THE INVENTION
The present invention was developed to overcome the above-mentioned drawbacks of the prior art and has an object to provide a cesium-lithium-borate crystal and crystals with substituted chemical compositions which are high-performance frequency converting nonlinear optical crystals that pass shorter wavelengths, have a high conversion efficiency, and have a large temperature and angular allowance, a method for manufacturing such crystals, and a method for utilizing same.
As means to solve the above-mentioned problem, the present invention provides a cesium-lithium-borate crystal having a chemical composition expressed as CsLiB
6
O
10
.
The present invention provides also a substituted cesium-lithium-borate crystal having a chemical composition expressed by the following formula:
Cs
1−x
Li
1−y
M
x+y
B
6
O
10
(where, M is at least one alkali metal element other than Cs and Li, and x and y satisfy the relationship of 0≦x≦1 and 0≦y≦1, and x and y never take simultaneously a value of 0 or 1), or the following formula
Cs
2(1−z)
Li
2
L
z
B
12
O
20
(where, L is at least one alkaline earth metal element, and 0<z<1)
Furthermore, the present invention provides also a method for manufacturing the above-mentioned crystals by heating and melting a raw material mixture of constituent elements, a method for manufacturing the above-mentioned crystals through growth by the melt methods comprising the crystal pulling method and top seeded kyropoulos method, and a method for manufacturing the above-mentioned crystals through growth by the flux method.
The present invention furthermore provides a frequency converter and an optical parametric oscillator provided with the above cesium-lithium-borate crystal or the crystal With a substituted chemical composition as optical means.
REFERENCES:
patent: 3934154 (1976-01-01), Cook, Jr.
patent: 4867956 (1989-09-01), Boryta et al.
patent: 5104845 (1992-04-01), Montag et al.
patent: 5144630 (1992-09-01), Lin
patent: 5191587 (1993-03-01), Hanson et al.
patent: 5381754 (1995-01-01), Wu et al.
patent: 5390211 (1995-02-01), Clark et al.
patent: 5684813 (1997-11-01), Keszler
patent: 5742626 (1998-04-01), Mead et al.
Mori, et al, “Growth of a nonlinear . . . ,” J. of Crys. Growth, 156, pp. 307-309, 1995, no month.*
Mori et al, “Nonlinear Optical Properties . . . ,” Jpn. J. Appl. Phys. vol. 34, pp. L296-L298, Part 2, No. 3A, Mar., 1995.*
Tn, et al, “CsLiB6O10 : A Noncentrosymmetric Polyborate”, Mat. Res. Bull., vol. 30, No. 2, pp. 209-215, 1995, Feb.*
Sasaki, et al., “New Nonlinear Optical Crystal Cesium Lithium Borate” OSA Proceedings on Advanced Solid State Lasers, vol. 24, pp. 91-95, Jan. 1995.
Hiraki Akio
Mori Yusuke
Nakai Sadao
Sasaki Takatomo
Bos Steven
Research Development Corporation of Japan
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Cesium-lithium-borate crystal and its application to... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cesium-lithium-borate crystal and its application to..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cesium-lithium-borate crystal and its application to... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2594609