Light guide plates and backlight modules thereof

A light guide plate, comprising:

• a light incident surface;
• a transmission layer;
• a light emission surface;
• wherein a light waveguide layer is configured within the transmission layer to change a transmission direction of at least a portion of light beams entered from the light incident surface along a direction perpendicular to the light emission surface;
• at least one periodic microstructure is configured on the light emission surface.

A backlight module, comprising:

• a light source;
• and
• a light guide plate;
• wherein the light guide plate is configured with a light incident surface, a transmission layer, and a light emission surface;
• a light waveguide layer is configured within the transmission layer to change a transmission direction of at least a portion of light beams entered from the light incident surface along a direction perpendicular to the light emission surface;
• at least one periodic microstructure is configured on the light emission surface;
• the light source corresponds to the light incident surface of the light guide plate.