Optical laser communication apparatus with optical phased arrays and coupling arrangement and associated methods
An optical communications transmitter for use in free space communication from the transmitter to a receiver, the transmitter including a light input and an optical fiber array for directing the light input. The optical communications transmitter further includes an optical phased array for receiving the light input from the optical fiber array and transmitting a light output, the optical phased array being configured for modifying a relative phase of the light input such that the light output exhibits a predetermined far-field intensity pattern.
1. An optical receiver for use in free space communication from a transmitter to the optical receiver, the optical receiver comprising:
an external window configured for passing visible light as well as optical signals of communication wavelengths therethrough;
an optical switch;
a waveguide;
a receiver; and
an internal window,
the optical switch being configured for redirecting optical signals received at the external window from a plurality of different incidence angles into an input ray having an angle within a range of acceptance angles for the waveguide;
the optical switch being further configured to compensate for differences in pulse arrival time of the optical signals from the plurality of different incidence angles at the external window, depending on incidence angle at which a particular optical signal is incident at the external window; and
the waveguide being configured for selectively directing optical signals incident thereon toward the receiver, while passing visible light through to the internal window.
2. The optical receiver of claim 1 , further comprising a coating on the internal window for blocking the optical signals from passing through the internal window.
3. The optical receiver of claim 1 , wherein the optical switch is a liquid crystal optical angle switch.
4. The optical receiver of claim 1 , wherein the optical switch is configured for compensating for differences in optical path lengths of the optical signals received from the plurality of different incidence angles.
5. The optical receiver of claim 4 , further comprising a compensator for providing additional optical path length compensation.
6. The optical receiver of claim 5 , wherein the compensator is adjustable.
7. The optical receiver of claim 1 , wherein the waveguide includes a holographic layer.
8. The optical receiver of claim 1 , wherein the range of acceptance angles is configured for receiving input rays from at least one of a satellite, a ground station, an aircraft, an unmanned autonomous vehicle (UAV), a ground vehicle, and a nautical vessel.
9. The optical receiver of claim 1 , wherein the waveguide is split into at least two sections.
10. The optical receiver of claim 9 , further comprising at least two receivers, wherein each one of the at least two sections of the waveguide is configured for directing the input ray received thereon into one of the at least two receivers.
11. The optical receiver of claim 10 , wherein the optical switch is further configured for directing the input ray toward one of the at least two sections of the waveguide according to the incidence angle at which the particular optical signal is incident at the external window, such that each one of the at least two sections of the waveguide accepts the input ray with substantially same time delay.
12. The optical receiver of claim 10 , wherein each one of the at least two receivers is configured for introducing a relative time delay with respect to each other one of the at least two receivers to take into account differences in optical pathlengths traveled by the optical signals received at different sections of the external window.