Ceramic Lasers of Normal and Composite Type
|Akio Ikesue 2, Kunio Yoshida 1, Tomosumi Kamimura 1, Yan Lin Aung 2, Taira Takunori 3|
1. Osaka Institute of Technology, Osaka 535-8585, Japan
For the important four-level solid-state laser host, a YAG (Y3Al5O12) single crystal, a small content of fluorescent Nd3+ ions are used as active species in the 1064 nm wavelength. In recent years, a Nd-doped YAG laser has been applied widely in various industrial capacities, including medical operation, metal processing, and other applications.
The present author demonstrated in 1994 that the effective laser oscillation was performed successfully for the first time in the world using polycrystalline Nd:YAG. The present work can be summarized as follows.
(1)High-quality Nd:YAG ceramics were fabricated successfully by simple solid-state reaction under vacuum sintering.
(2)Such properties of Nd:YAG ceramics as thermo-mechanical properties were nearly the same as those of Nd:YAG single crystal by Cz method.
(3)Optical loss of Nd:YAG ceramics was 0.9%cm-1, as low as that of Nd:YAG single crystal.
We have developed successfully most advanced composite laser media which perfectly bonded both single crystal and polycrystalline ceramics. The bonding interfaces between single crystal and ceramics become almost "Stealth" or " Seam-less" conditions, because the interface has no interstice and migrates towards polycrystalline ceramics by sudden grain growth. The advanced composite was confirmed almost optically perfect bonding by interferometory.
To obtain higher laser function, the composite laser using single crystals was developed in 1998, however several problems existed in conventional composite because of unperfected bonding. The narrow interstices (<λ) partially exist in interface of conventional composite composed of single crystals, so it has some problems such as optical loss, thermal diffusion, lifetime etc. We challenge to fabricate new composite laser media having more improved bonding interface, which composed of polycrystalline ceramic and single crystal.
Presentation: invited oral at E-MRS Fall Meeting 2005, Laser Ceramic Symposium, by Akio Ikesue
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-05-19 00:55 Revised: 2009-06-07 00:44