| abstract |
This invention provides a light transparent ceramic that has a high Abbe number, can be used advantageously for aberration correction, and can easily manufactured. The light transparent ceramic is characterized by comprising, as a main component, a garnet-type compound represented by general formula: Y3AlvOw, wherein 4.4 & v & 5.4; and w represents a positive number for maintaining an electrically neutral state, a part or the whole of Al in Y3AlvOw having been replaced with Ga. This light transparent ceramic is suitable, for example, for lenses (22, 25) disposed so that a diaphragm (28) is held between the lenses, in a gauss-type optical system (20), for example, an optical system for single-lens reflex cameras. |