An apparatus includes a write head comprising a near-field transducer at a media-facing surface of the write head and a waveguide extending along a light-propagation direction. The waveguide is configured to receive light emitted from a light source at a fundamental transverse electric mode. The waveguide is configured to deliver the light to the near-field transducer at a transverse magnetic mode which directs surface plasmons to a recording medium in response thereto. The waveguide comprises a core with first and second tapers separated by a straight portion of constant cross sectional width. The first and second tapers successively decrease a cross-sectional width of the core as it nears the near-field transducer. The waveguide includes an end portion between the second taper and the near field transducer. The end portion comprises a top cladding layer, aside cladding layer, and a bottom cladding layer on the side cladding layer.