An apparatus comprises a slider configured for heat-assisted magnetic recording comprising an air bearing surface (ABS). The slider comprises a write pole at or near the ABS, and a near-field transducer (NFT) at or near the ABS and proximate the write pole. A main waveguide is configured to receive light from a laser source and communicate the light to the NFT. An optical power sensor comprises a tap waveguide optically coupled to the main waveguide and comprising a first end and an opposing second end. The optical power sensor also comprises a bolometer optically coupled to the tap waveguide and configured to receive a portion of the light extracted from the main waveguide by the tap waveguide.