Thermally-assisted magnetic recording head having main waveguide and sub-waveguides

摘要

A waveguide structure for aligning a light source to a center waveguide (CWG) in a TAMR head is disclosed and includes two alignment waveguides (AWVG) symmetrically formed about a plane that bisects the CWG lengthwise dimension. Each AWVG has a light coupling section formed parallel to a side of the CWG and captures 0.5% to 10% of the light in the CWG. Each AWVG has an outlet that directs light to a photo detector or camera so that light intensity measurements l_AWVG1 and l_AWVG2 for first and second AWVG, respectively, can be taken at various positions of the light source. Optimum alignment occurs when (l_AWVG1+l_AWVG2) reaches a maximum value and |l_AWVG1−l_AWVG2| has a minimum value. AWVG outlets may be at the ABS, or at the side or back end of a slider. Measurement sensitivity is increased by decreasing the width of the AWVG.