Glass composite material, precursor thereof, nitrogen-containing composite material and optical device

An optical device having an optical functional material as a constitutional element, wherein the optical functional material comprising a polymer chain selected from the group consisting of polysilane, polygermane, polystannane and a copolymer thereof, and a network structure of a metal oxide consisting of a metal atom bonded to another metal atom through an oxygen atom;

• wherein the polymer chain is chemically crosslinked with a glass matrix of the network structure of the metal oxide at three or more positions directly or indirectly, resulting in a cured state;
• and an area of signals due to a silicon, germanium or stannum crystal observed within a range of 20 to 60 degrees of 2 .theta. is not more than 1% of the total area of the all signals according to a X-ray diffraction using a Cu tubular bulb as a X-ray source.