Planar waveguides with air thin films used as anti-reflective layers, beam splitters and mirrors

A planar light wave circuit comprising:

• a waveguide comprising
• a core sandwiched between a lower cladding and an upper cladding,
• an anti-reflective element in the core comprising a pair of spaced apart slits traversing the core, the slits each being filled with air, the two slits being perpendicular to an axis of the core and transmitting an optical beam extending down the core that engages the air disposed within the slits.

The waveguide of claim 18 wherein the slits are formed using focused ion beams.

A planar light wave circuit comprising:

• a waveguide comprising
• a core sandwiched between a lower cladding and an upper cladding,
• an anti-reflective element integrated into the core and comprising a pair of spaced apart high aspect ratio slits traversing the core, the slits each being filled with air, the two slits being perpendicular to an axis of the core and transmitting an optical beam extending down the core that engages the air disposed within the slits, the slits being formed using focused ion beams.