Patent ID: 7580075

Claim:
An optical device, comprising: an adapter having a tubular portion; a translucent member attached to a first surface of the tubular portion of the adapter, the first surface facing against the direction of incoming light; an optical element chip placed at a position on the adapter which faces the translucent member; an alignment step formed in the tubular portion of the adapter, and a mirror tube fitting into the alignment step, wherein an outer perimeter end surface of the translucent member is located on the first surface, a sealing member is formed on the outer perimeter end surface of the translucent member, an outer perimeter end surface of the sealing member and a surface of the alignment step of the adaptor parallel to the outer perimeter end surface of the translucent member lie in a same plane, the outer perimeter end surface of the sealing member and the surface of the alignment step of the adaptor are attached to an inner surface of the mirror tube.