Glass materials for optical gain media and infrared optics comprising rare earth oxide glass compositions

Abstract

This invention relates to the use of novel glass materials comprising rare earth aluminate glasses (REAl™ glasses) in the gain medium of solid state laser devices that produce light at infrared wavelengths, typically in the range 1000 to 3000 nm and for infrared optics with transmission to approximately 5000 nm in thin sections. The novel glass materials provide stable hosts for trivalent ytterbium (Yb3+) ions and other optically active species or combinations of optically active species that exhibit fluorescence and that can be optically excited by the application of light. The glass gain medium can be configured as a waveguide or placed in an external laser cavity, or otherwise arranged to achieve gain in the laser waveband and so produce laser action.

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0001] This invention was made with government support under contract number DMI-0216324 awarded by the National Science Foundation and contract number F49620-02-C-0028 awarded by the Air Force Office of Scientific Research. The Government has certain rights in this invention.FIELD OF INVENTION [0002] This invention relates to solid state lasers that use novel glass compositions, comprising rare earth oxides and aluminum oxide (the REAl™ glasses) doped with optically active species, as the gain medium. It further relates to lasers based on these glass compositions that emit infrared light in the wavelength range from approximately 1000 to 3000 nm through the application of pump radiation at a wavelength of 970 nm to 990 nm, and preferably about 980 nm. It further relates to the use of REAl™ glasses that can be cast in the form of “blanks” that form components of laser gain media and windows, filters, or lenses that tran...

AI Technical Summary

Benefits of technology

[0013] The invention is an optical gain medium comprising a bulk single phase glass. The bulk single phase glass comprises 27 to 50 molar % RE203 and 50 to 73 molar % Al2O3, where RE is one or more elements selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. The optical gain medium may be used in a manner such that gain is generated by application of light in the wavelength range from 970-990 nm. The optical gain medium may be doped with ytterbium ions or other dopant ions such as Er, Tm or Ho. Gain may be generated by electronic transitions of Yb or other dopant ions such as Er, Tm or Ho.

[0014] In a second aspect of the invention, the invention is an optical gain medium consisting essentially of a bulk single phase glass comprising one or more rare earth oxides, aluminum oxide and silicon dioxide wherein the composition of the bulk single phase glass lies substantially within the heptagonal region of the ternary composition diagram of the rare earth oxide-alumina-silica system defined by points having the following molar percent compositions: 1% RE2O3, 59% Al2O3 and 40% SiO2; 1% RE2O3, 71% Al2O3 and 28% SiO2; 23% RE2O3 and 77% Al2O3; 50% RE2O3 and 50% Al2O3; 50% RE2O3 and 50% SiO2; 33.3% RE2O3, 33.33% Al2O3 and 33.33% SiO2; and 16.67% RE2O3, 50% Al2O3 and 33.33% SiO2. The optical gain medium may be used in a manner such that gain is generated by application of light in the wavelength range from 970-990 nm. The optical gain medium may be doped with ytterbium ions or other ions such as Er, Tm or Ho. Gain may be generated by electronic transitions of Yb, Er, Tm of Ho.

[0015] In a third aspect of the invention, the invention is an optical material consisting essentially of a bulk single phase glass comprising 27 to 50 molar % RE2O3 and 50 to 73 molar % Al2O3, where RE is one or more elements selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu and wherein the glass is formed by casting of a molten material.

[0016] In a fourth aspect of the invention, the invention is an optical material consisting essentially of a bulk single phase glass comprising one or more rare earth oxides, aluminum oxide and silicon dioxide wherein the composition lies substantially within the heptagonal region of the ternary composition diagram of the rare earth oxide-alumina-silica system defined by points having the following molar percent compositions: 1% RE203, 59% Al2O3 and 40% SiO2; 1% RE2O3, 71% Al2O3 and 28% SiO2; 23% RE2O3 and 77% Al2O3; 50% RE2O3 and 50% Al2O3; 50% RE2O3 and 50% SiO2; 33.33% RE2O3, 33.33% Al2O3 and 33.3% SiO2; and 16.67% RE2O3, 50% Al2O3 and 33.33% SiO2, where RE is one or more elements selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb and Lu and wherein the glass is formed by casting of a molten material.

Problems solved by technology

The close spacing of the absorption and emission bands in Yb3+ results in small conversion losses.

Images