Structured light illumination module

A structured light illumination module for three dimension sensing, comprising:

• a light source including a laser diode and configured for emitting light;
• an truncated conical optical element including an incident surface, an emergent surface, and a lateral surface, wherein each of the incident surface and the emergent surface has a light transmissive zone which receives the light emitted from the light source and allows collimated light emitted from the light source to pass, and an angle θ between the lateral surface and an optical axis of the optical element is configured for totally internally reflecting at least a part of the light emitted from the light source by the lateral surface;
• a structured light diffractive component configured for converting the light emitted from the optical element into a structured light pattern, and spaced apart from the optical element;
• and
• an energy recycling mechanism disposed on at least a part of the incident surface of the optical element or at least a part of the emergent surface of the optical element.