US 12,148,458 B1
Assist cores for spot size converter for heat assisted magnetic recording
Norman Nan Shi, Los Altos, CA (US); Takuya Matsumoto, San Jose, CA (US); and Barry C. Stipe, San Jose, CA (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Jul. 18, 2023, as Appl. No. 18/354,439.
Claims priority of provisional application 63/506,884, filed on Jun. 8, 2023.
Int. Cl. G11B 5/60 (2006.01); G02B 6/122 (2006.01); G11B 5/48 (2006.01); G11B 13/08 (2006.01); G11B 5/00 (2006.01)
CPC G11B 5/6088 (2013.01) [G02B 6/1228 (2013.01); G11B 5/4866 (2013.01); G11B 13/08 (2013.01); G11B 2005/0021 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A magnetic recording head assembly, comprising:
a main pole;
a near field transducer (NFT) disposed adjacent to the main pole; and
a spot size converter coupled to the NFT, wherein the spot size converter comprises:
a first waveguide coupled to the NFT;
a multimodal interference (MMI) device having a first end and a second end, wherein the first end is coupled to the first waveguide; and
a plurality of split assist core structures coupled to the second end, wherein the plurality of split assist core structures extend from the MMI device to a top surface of the head assembly, the top surface being opposite a media facing surface (MFS) of the head assembly, and wherein each split assist core structure comprises a main waveguide and a plurality of assist cores.