Dual self-mixing interferometry device and method

A detection device, comprising:

• a first electromagnetic radiation device, configured to emit first electromagnetic radiation toward a target at a first time period, to receive a reflection of the first electromagnetic radiation from the target emitted at the first time period, and to modulate first electromagnetic radiation emitted at a second time period by the received reflection of the first electromagnetic radiation;
• a second electromagnetic radiation device, configured to emit second electromagnetic radiation toward a target at the first time period, to receive a reflection of the second electromagnetic radiation from the target emitted at the first time period, and to modulate second electromagnetic radiation emitted at a second time period by the received reflection of the second electromagnetic radiation, wherein the second electromagnetic radiation device is a predetermined distance from the first electromagnetic radiation device;
• and
• a processor, configured to determine an angular velocity of the target based on a first electrical signal representing the modulated first electromagnetic radiation, a second electrical signal representing the modulated second electromagnetic radiation, and the predetermined distance.