Optical coupler comprising a molded optical interposer together with a PIC and 2 polarization selective elements enabling isolation and/or polarization management

An optical interposer apparatus comprising:

• a first and second lens and a first polarization selective reflector or filter coupling light from a second optical element to a photonic integrated circuit or from a photonic integrated circuit to a second optical element, the photonic integrated circuit comprising a first and second coupler, a first and second polarization selective element adapted to transmit different polarizations, wherein the first and second couplers are edge couplers and respectively connected with the first and second polarization selective elements, wherein:
• light propagates from the second optical element to the first lens, from the first lens to the first polarization selective reflector or filter, from the first polarization selective reflector or filter to the second lens, from the second lens to the first coupler, or in the reverse order;
• and
• light is coupled from the second optical element to the first coupler for one polarization and coupled to the second coupler for another polarization;
• light is coupled from the first coupler into the second optical element with one polarization and coupled from the second coupler into the second optical element with another polarization;
• light is coupled from the second optical element to the first coupler and the second optical element is isolated from reflections occurring at or after the first coupler;
• or
• light is coupled from the first coupler to the second optical element and the photonic integrated circuit is isolated from reflections occurring at or after the second optical element.

An optical interposer apparatus comprising:

• a first and second lens and a first polarization selective reflector or filter coupling light from a second optical element to a photonic integrated circuit or from a photonic integrated circuit to a second optical element, the photonic integrated circuit comprising a first polarization selective coupler or a first coupler connected to a polarization selective subsystem, wherein:
• a free beam propagates inside the optical interposer and is not constrained by guiding in a waveguide, the free beam is collimated or near-collimated, a distribution of k-vectors of the free beam are substantially narrower than that of beams emitted or received by the second optical element and the first polarization selective coupler or the first coupler connected to a polarization selective subsystem, the free beam reaches the first polarization selective reflector or filter;
• light propagates from the second optical element to the first lens, from the first lens to the first polarization selective reflector or filter, from the first polarization selective reflector or filter to the second lens, from the second lens to the first coupler, or in the reverse order;
• and
• light is coupled from the second optical element to the first coupler for one polarization and coupled to a second coupler of the photonic integrated circuit for another polarization;
• light is coupled from the first coupler into the second optical element with one polarization and coupled from a second coupler of the photonic integrated circuit into the second optical element with another polarization;
• light is coupled from the second optical element to the first coupler and the second optical element is isolated from reflections occurring at or after the first coupler;
• or
• light is coupled from the first coupler to the second optical element and the photonic integrated circuit is isolated from reflections occurring at or after the second optical element.