| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide improved spinel materials suited for optical applications, and to provide improved methods for forming the same. <P>SOLUTION: A single crystal spinel boule is formed by melt processing. The boule has a non-stoichiometric composition and has a reduced mechanical stress or strain. The reduced mechanical stress is represented by a yield rate, not less than about 20%. Yield rate is defined by W<SB POS="POST">i</SB>/(W<SB POS="POST">i</SB>+W<SB POS="POST">f</SB>)×100%, where W<SB POS="POST">i</SB>is equal to the number of intact wafers processed from the boule, and W<SB POS="POST">f</SB>is equal to the number of fractured wafers from the boule due to internal mechanical stress or strain in the boule. A single crystal spinel material has a non-stoichiometric composition and has a transparency window represented by absorptivity over a wavelength range. The wavelength range normally extends from about 400 nm to about 800 nm. The transparency window is defined as the largest single absorptivity peak height along the wavelength range, the largest single peak height being not greater than 0.35 cm<SP POS="POST">-1</SP>. <P>COPYRIGHT: (C)2012,JPO&INPIT |
