There is provided a device (100) for use in measuring blood pressure. The device (100) comprises a light source (102) configured to emit light (104) onto the skin (106) of a subject (108). The light source (102) is configured to alternate between emitting coherent light and incoherent light. The device (100) also comprises a light detector (110) configured to detect light (104) scattered back from the skin (106) of the subject (108) and generate an electrical signal from the detected light. The generated electrical signal is for use in measuring a blood pressure of the subject (108).
