A method and apparatus for focusing light within a waveguide is provided. The waveguide includes a curved grating adapted to focus light incident thereon to a focused spot proximate a first end of the waveguide. In another embodiment, the first end of the waveguide has a thickness greater than a portion of the waveguide containing the grating. The waveguide is suitable for focusing light onto a magnetic storage medium and the like, making the waveguide suitable for heat-assisted magnetic recording (HAMR) applications.