Integrated optical filter

An integrated optical device, comprising:

• an optical microguide of index n0 between two layers of respective refractive indices n1 and n′1, such that n1<n0 and n′1<n0, said optical microguide having an optical path carrying an optical signal, and
• a filtering device configured to filter stray light which propagates in the vicinity of the optical microguide, in the plane of said layers, said filtering device comprising at least one reflector element placed outside said optical path on at least one side of the optical microguide, said at least one reflector element having a surface inclined with respect to said optical path and oriented to reflect stray light away from said optical axis, said at least one reflector element having at least one element etched in the layers of index n1 and/or n′1 and/or n0.