The present invention relates to a technique for intercepting light which is emitted from a connection reception side optical connector which is housed inside a connector hole of a connector housing of a device such as an optical connector adapter or the like using a shutter, and more particularly relates to a development of this technology which makes it possible to arrange the shutter without exerting the negative effect of increasing the size of the connector housing. With the present invention such light interception is implemented, without increasing the size of the connector housing 14, by providing a structure in which a shutter unit is fitted within a connector hole 14a of a connector housing 14, with this shutter unit comprising two shutter leaves 53A and 53B for light interception supported upon shafts in a main section 51 of the assembly. Furthermore it is possible to guarantee the dust interception characteristic of the connector hole, since the plurality of shutter leaves 53A and 53B mutually overlap with one another so as to close off the connector hole 14a when they are in their light interception positions.