Method for producing composite optical ceramic element

A method of manufacturing a composite optical ceramic element including a first ceramic section and a second ceramic section joined to the first ceramic section, the method comprising:

• a first process of preparing a first powder that contains a first transition element and is for the first ceramic section, and a second powder that is different from the first powder in a concentration of the first transition element and is for the second ceramic section;
• a second process of disposing the first powder in a first region, disposing the second powder in a second region adjacent to the first region, and bringing the first powder and the second powder into contact with each other at a boundary portion between the first region and the second region to form a contacting state after the first process;
• and
• a third process of sintering the first powder and the second powder while maintaining the contacting state to respectively form the first ceramic section and the second ceramic section from the first powder and the second powder after the second process, thereby forming a composite body.