Three-dimensional distance information acquisition system and electronic device including the same
A three-dimensional (3D) distance information acquisition system and an electronic device including the same are provided. The 3D distance information acquisition system includes: a transmitter including a light source configured to emit a light based on a time division method and a spatial light modulator configured to steer the light incident from the light source to each scan point on an object; a receiver including a photodetector configured to detect the light reflected from the scan point of the object; and a processor configured to obtain 3D distance information based on the light detected by the receiver.
1 . A three-dimensional (3D) distance information acquisition system comprising:
a transmitter comprising a light source configured to emit a light based on a time division method and a spatial light modulator configured to steer the light incident from the light source to each scan point on an object;
a receiver comprising a photodetector configured to detect the light reflected from the scan point of the object; and
a processor configured to obtain 3D distance information based on the light detected by the receiver,
wherein the spatial light modulator comprises:
a first material layer;
a cavity provided on an entirety of a surface of the first material layer, the light incident being resonated in the cavity; and
a second material layer comprising a grating structure provided on the cavity, and
wherein the second material layer comprises:
a first doped semiconductor layer contacting the cavity;
an intrinsic semiconductor layer contacting the first doped semiconductor layer; and
a second doped semiconductor layer contacting the intrinsic semiconductor layer.
2 . The 3D distance information acquisition system of claim 1 , wherein the spatial light modulator comprises a plurality of pixels for steering the light incident by phase modulation, and each of the plurality of pixels comprises a stacked structure comprising the first material layer, the cavity, and the second material layer.
3 . The 3D distance information acquisition system of claim 1 , wherein the grating structure comprises any one of a positive-intrinsic-negative (PIN) semiconductor structure, a negative-intrinsic-negative (NIN) semiconductor structure, and a positive-intrinsic-positive (PIP) semiconductor structure.
4 . The 3D distance information acquisition system of claim 1 , wherein the cavity comprises SiO2, and the grating structure comprises a PIN structure comprising Si.
5 . The 3D distance information acquisition system of claim 1 , wherein a pitch of the grating structure is less than a wavelength of the light modulated by the spatial light modulator.
6 . The 3D distance information acquisition system of claim 1 , wherein the first material layer comprises a distributed Bragg reflector.
7 . The 3D distance information acquisition system of claim 6 , wherein the first material layer comprises a structure in which Si layers and SiO2 layers are repeatedly stacked.
8 . The 3D distance information acquisition system of claim 1 , wherein the spatial light modulator is provided to modulate a phase by controlling a resonance condition by changing a refractive index of the grating structure by external electric stimulation.
9 . The 3D distance information acquisition system of claim 1 , wherein the spatial light modulator is a transmissive type or a reflective type.
10 . The 3D distance information acquisition system of claim 1 , wherein the light source comprises any one of an edge emitting laser, a vertical cavity surface emitting laser, and a photonic crystal surface emitting laser.
11 . The 3D distance information acquisition system of claim 1 , wherein the transmitter further comprises a collimating lens configured to collimate the light emitted from the light source.
12 . The 3D distance information acquisition system of claim 1 , wherein the transmitter further comprises an outgoing optical system, and the outgoing optical system comprises a diverging lens configured to expand a range of beam steering by the spatial light modulator.
13 . The 3D distance information acquisition system of claim 12 , wherein the diverging lens comprises a concave lens or a cylinder lens in which at least one lens surface is concave.
14 . The 3D distance information acquisition system of claim 1 , wherein the photodetector comprises any one of a silicon photomultiplier (SiPM), an avalanche photo diode (APD), and a single photon avalanche diode (SPAD).
15 . The 3D distance information acquisition system of claim 1 , wherein, when a direction in which the light emitted from the light source proceeds towards the spatial light modulator is a first proceeding direction, and a direction in which the light steered by the spatial light modulator proceeds is a second proceeding direction,
the spatial light modulator is disposed to be inclined with respect to a plane that extends in the first proceeding direction and the second proceeding direction.
16 . The 3D distance information acquisition system of claim 1 , wherein, when a direction in which the light emitted from the light source proceeds towards the spatial light modulator is a first proceeding direction, and a direction in which the light steered by the spatial light modulator proceeds is a second proceeding direction,
the spatial light modulator is disposed to be perpendicular to a plane that extends in the first proceeding direction and the second proceeding direction, and
further comprises an inclined mirror member configured to reflect the light steered by the spatial light modulator in a direction out of the plane.
17 . An electronic device comprising at least one sensor of a distance sensor, a three-dimensional (3D) sensor, and a light detection and ranging (LiDAR) sensor,
wherein the 3D distance information acquisition system of claim 1 is provided as the at least one sensor.
18 . The electronic device of claim 17 , wherein the at least one sensor comprises a LiDAR sensor or a depth camera for a mobile device.
19 . A distance sensor comprising:
a transmitter comprising:
a light source configured to turn on all semiconductor-based laser diodes of the light source at each scan time, and emit a collimated pencil beam using the semiconductor-based laser diodes at each scan time; and
a spatial light modulator configured to steer the collimated pencil beam incident from the light source to each scan point on an object;
a receiver comprising a photodetector configured to detect light reflected from the scan point of the object; and
a processor configured to obtain 3D distance information based on the light detected by the receiver,
wherein the spatial light modulator comprises:
a first material layer;
a cavity provided on an entirety of a surface of the first material layer, the light incident being resonated in the cavity; and
a second material layer comprising a grating structure provided on the cavity, and
wherein the second material layer comprises:
a first doped semiconductor layer contacting the cavity;
an intrinsic semiconductor layer contacting the first doped semiconductor layer; and
a second doped semiconductor layer contacting the intrinsic semiconductor layer.