Sonos Optical Audio Adapter Optical digital audio to HDMI adapter cable at Crutchfield
Amazon.com: 10Gtek A Pair of HDMI to Fiber Optic Converter, HDMI Extender with SFP+ Transceiver, SFP+ LR Lite Module up to 2km Link Length, Support HDMI 1.4a, 4Kx2K@30Hz : Electronics
High-Speed HDMI Active Optical Cable w/ Detachable Connector
HDMI Audio Extractor, 4K@60Hz HDMI to HDMI + Optical Toslink SPDIF + 3.5mm AUX | eBay