An optical assembly (100) for use in a wearable device is provided, the assembly (100) comprising: a prism (104), a photonic integrated chip, PIC (108), a substrate layer (106), and a lid (102); wherein the PIC (108) is mounted onto the substrate layer (106); the prism (104) comprising: (i) a first input/output surface (112) optically coupled to the PIC (108), and (ii) a second input/output surface (114) optically coupled to the lid (102), the second input/output surface (114) orientated perpendicularly to the first input/output surface (112), and wherein the prism (104) provides an optical path and reflects a percentage of light from the first input/output surface (112) to the second input/output surface (114). Methods of manufacturing such an optical assembly are also provided.