US 12,411,367 B2
Composite substrate for electro-optical element
Ryosuke Hattori, Ichinomiya (JP); Tomoyoshi Tai, Inazawa (JP); Keiichiro Asai, Nagoya (JP); and Jungo Kondo, Miyoshi (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK INSULATORS, LTD., Nagoya (JP)
Filed on Feb. 2, 2022, as Appl. No. 17/649,682.
Application 17/649,682 is a continuation of application No. PCT/JP2021/019037, filed on May 19, 2021.
Claims priority of application No. 2020-088349 (JP), filed on May 20, 2020.
Prior Publication US 2022/0155619 A1, May 19, 2022
Int. Cl. G02F 1/035 (2006.01); G02B 6/12 (2006.01)
CPC G02F 1/035 (2013.01) [G02B 6/12 (2013.01); G02B 2006/12142 (2013.01); G02F 2202/09 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A composite substrate for an electro-optical element, comprising: an electro-optical crystal substrate having an electro-optical effect; a first high dielectric layer; a second high dielectric layer; and a support substrate in the stated order,
wherein the first high dielectric layer and the second high dielectric layer are directly joined to each other,
wherein an amorphous layer is formed at a joining interface between the first high dielectric layer and the second high dielectric layer,
wherein the first high dielectric layer is directly formed on the electro-optical crystal substrate, and the second high dielectric layer is directly formed on the support substrate, and
wherein the support substrate contains silicon oxide as a main component, and an argon concentration in the support substrate is 0.1 atomic % to 1.0 atomic %.