Abstract: An optical sensing module suitable for wearable devices, the optical sensing module comprising: a silicon or silicon nitride transmitter photonic integrated circuit (PIC), the transmitter PIC comprising: a plurality of lasers, each laser of the plurality of lasers operating at a wavelength that is different from the wavelength of the others; an optical manipulation region, the optical manipulation region comprising one or more of: an optical modulator, optical multiplexer (MUX); and additional optical manipulation elements; and one or more optical outputs for light originating from the plurality of lasers.

Abstract: A rotor disc for use in an electrical machine has circumferential rotor rims mounted thereon. The rotor rim comprises a row of alternate magnets and pole pieces. The magnets are tapered at their radially inner and outer extents and engage with correspondingly tapered surfaces on adjacent pole pieces to prevent relative physical movement therebetween.Each side of the radially inner and outer extents of the magnets may be tapered by a different amount to ensure correct orientation of the magnet polarity.