US 11,657,845 B1
Beam combiner for VCSEL array in HAMR head
Norman N. 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 Mar. 30, 2022, as Appl. No. 17/708,558.
Int. Cl. G11B 5/48 (2006.01); G11B 13/08 (2006.01); G11B 5/00 (2006.01)
CPC G11B 13/08 (2013.01) [G11B 2005/0021 (2013.01)] 20 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 at a media facing surface;
a vertical cavity surface emitting laser (VCSEL) device coupled to a top surface of the magnetic recording head assembly, the top surface opposite a media facing surface of the magnetic recording head assembly; and
a waveguide structure coupled between the NFT and the VCSEL device, the waveguide structure comprising:
a waveguide coupled to the NFT;
a multimodal interference (MMI) combiner having a first end coupled to the waveguide; and
a plurality of waveguide channels coupled to a second end the MMI combiner opposite the first end of the MMI combiner, wherein each of the plurality of waveguide channels has a different curvature such that each of the plurality of waveguide channels is phase coherent with adjacent waveguide channels.