THREE-DIMENSIONAL BEAM STEERING DEVICE
A device includes a stack of a lens assembly and a steering assembly. The stack is configured to receive a beam from a first side and output the beam from a second side. The lens assembly is configured to provide an adjustable optical power to the beam. The steering assembly is configured to provide an adjustable steering angle to the beam. The device also includes a reflector configured to receive the beam output from the second side of the stack, and reflect the beam back to the second side of the stack. The beam reflected back from the reflector is incident onto the second side of the stack, and output from the first side of the stack.
1 . A device, comprising:
a stack of a lens assembly and a steering assembly, the stack configured to receive a beam from a first side and output the beam from a second side, wherein the lens assembly is configured to provide an adjustable optical power to the beam, and the steering assembly is configured to provide an adjustable steering angle to the beam; and
a reflector configured to receive the beam output from the second side of the stack, and reflect the beam back to the second side of the stack,
wherein the beam reflected back from the reflector is incident onto the second side of the stack, and output from the first side of the stack.
2 . The device of claim 1 , further comprising a controller configured to control the lens assembly to selectively provide one of a plurality of optical powers to the beam, and to control the steering assembly selectively to selectively provide one of a plurality of steering angles to the beam.
3 . The device of claim 1 , wherein the lens assembly and the steering assembly are linear polarization selective.
4 . The device of claim 1 , wherein the lens assembly and the steering assembly are circular polarization selective.
5 . The device of claim 4 , further comprising:
a waveplate disposed between the reflector and the stack and configured to provide a quarter-wave retardance to the beam; and
a polarization switch disposed between the steering assembly and the lens assembly and configured to switch or maintain a polarization of the beam.
6 . The device of claim 1 , wherein the lens assembly is linear polarization selective and the steering assembly is circular polarization selective.
7 . The device of claim 6 , further comprising:
a first waveplate disposed between the reflector and the stack and configured to provide a quarter-wave retardance to the beam;
a second waveplate disposed between the steering assembly and the lens assembly and configured to provide a quarter-wave retardance to the beam; and
a polarization switch disposed between the second waveplate and the lens assembly and configured to switch or maintain a polarization of the beam.
8 . The device of claim 1 , wherein the lens assembly is circular polarization selective and the steering assembly is linear polarization selective.
9 . The device of claim 8 , further comprising:
a waveplate disposed between the steering assembly and the lens assembly and configured to provide a quarter-wave retardance to the beam; and
a polarization switch disposed between the waveplate and the lens assembly and configured to switch or maintain a polarization of the beam.
10 . The device of claim 1 , wherein the beam has a same first polarization when incident onto the lens assembly from two sides of the lens assembly, and the beam has a same second polarization when incident onto the steering assembly from two sides of the steering assembly.
11 . The device of claim 1 , wherein the reflector includes a holographic optical element.
12 . The device of claim 11 , wherein the reflector is configured to maintain a linear polarization of the beam output from the second side of the stack when reflecting the beam back to the second side of the stack.
13 . The device of claim 11 , further comprising:
a waveplate disposed between the reflector and the stack and configured to convert a first circular polarization of the beam output from the second side of the stack into a linear polarization,
wherein the reflector is configured to maintain the linear polarization of the beam when reflecting the beam back to the second side of the stack, and
wherein the waveplate is configured to convert the linear polarization of the beam reflected back from the reflector into a second circular polarization orthogonal to the first circular polarization.
14 . The device of claim 1 , wherein
the lens assembly includes a plurality of lenses arranged in an optical series, at least one of the lenses being a variable lens, and
the steering assembly includes a plurality of gratings arranged in an optical series, at least one of the gratings being a switchable grating.
15 . A system, comprising:
an eye tracking device configured to obtain eye tracking information of an eye pupil;
a beam steering device, comprising:
a stack of a lens assembly and a steering assembly, the stack configured to receive a beam from a first side and output the beam from a second side; and
a reflector configured to receive the beam output from the second side of the stack, and reflect the beam back to the second side of the stack,
wherein the beam reflected back from the reflector is incident onto the second side and output from the first side of the stack; and
a controller configured to control, based on the eye tracking information, the stack to adjust at least one of a steering angle provided by the steering assembly or an optical power provided by the lens assembly to steer the beam to the eye pupil.
16 . The system of claim 15 , wherein the beam has a same first polarization when incident onto the lens assembly from two sides of the lens assembly, and the beam has a same second polarization when incident onto the steering assembly from two sides of the steering assembly.
17 . The system of claim 15 , wherein the reflector includes a holographic optical element.
18 . The system of claim 17 , wherein the reflector is configured to maintain a linear polarization of the beam output from the second side of the stack when reflecting the beam back to the second side of the stack.
19 . The system of claim 17 , further comprising:
a waveplate disposed between the reflector and the stack and configured to convert a first circular polarization of the beam output from the second side of the stack into a linear polarization,
wherein the reflector is configured to maintain the linear polarization of the beam when reflecting the beam back to the second side of the stack, and
wherein the waveplate is configured to convert the linear polarization of the beam reflected back from the reflector into a second circular polarization orthogonal to the first circular polarization.
20 . The system of claim 15 , further comprising:
a first waveplate disposed between the reflector and the stack and configured to provide a quarter-wave retardance to the beam;
a second waveplate disposed between the steering assembly and the lens assembly and configured to provide a quarter-wave retardance to the beam; and
a polarization switch disposed between the second waveplate and the lens assembly and configured to switch or maintain a polarization of the beam.