Lithium tantalate single-crystal and photo-functional device
AssigneeThe Regents of the University of California
InventorsVenkatraman Gopalan, Terence E. Mitchell, Kenji Kitamura, Yasunori Furukawa
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Abstract
Provided are lithium tantalate single-crystal that requires a low voltage of not larger than 10 kV/mm for its ferroelectric polarization inversion and of which the polarization can be periodically inverted with accuracy even at such a low voltage, and a photo-functional device comprising the crystal. The crystal has a molar fraction of Li2O/(Ta2O5+Li2O) of falling between 0.492 and 0.50. The functional device can convert a laser ray being incident thereon or can be used as a physical memory.
Claims7
A lithium tantalate single-crystal, which has a molar fraction of Li2O/(Ta2O5+Li2O) of falling between 0.492 and 0.50 and requires a voltage of not larger than 10 kV/mm for its ferroelectric polarization inversion.
A photo-functional device comprising lithium tantalate single-crystal, in which the polarization structure of the crystal is periodically inverted to thereby shorten or prolong the wavelength of the laser ray being incident on the device and falling from near UV to near infrared range, and which is characterized in that the lithium tantalate single-crystal has a molar fraction of Li2O/(Ta2O5+Li2O) of falling between 0.492 and 0.50.
A physical device comprising lithium tantalate single-crystal, in which the ferroelectric polarization of the crystal is inverted in a nanometer scale to thereby be used as a memory device, and which is characterized in that the lithium tantalate single-crystal has a molar fraction of Li2O/(Ta2O5+Li2O) of falling between 0.492 and 0.50 with low coercive field.
Dependencies are inferred from the claim text.