Method and apparatus for maintaining optical alignment for free-space optical communication

A method for use in optically communicating over free-space, comprising the steps of:

• receiving a receive optical beam through a narrow field of view at a first position of a first link head;
• determining a receive power level of the receive optical beam;
• shifting an alignment;
• maximizing the receive power;
• and
• transmitting a transmit optical beam along the alignment to a second link head, wherein the narrow field of view is less than a divergence of the transmit optical beam;
• wherein both the first and second link heads are capable of shifting alignment to maximize receive power levels at a same time and without having to communicate alignment information between them;
• wherein the narrow field of view is a narrow region of a multi-region field of view.

A method for use in optically communicating over free-space, comprising the steps of:

• receiving a receive optical beam through a narrow field of view at a first position of a first link head;
• determining a receive power level of the receive optical beam;
• shifting an alignment;
• maximizing the receive power;
• and
• transmitting a transmit optical beam along the alignment to a second link head, wherein the narrow field of view is less than a divergence of the transmit optical beam;
• wherein both the first and second link heads are capable of shifting alignment to maximize receive power levels at a same time and without having to communicate alignment information between them;
• further comprising the steps of:
• searching through a search pattern for the receive optical beam;
• and
• detecting the receive optical beam in the search pattern through a wide region of a multi-region field of view.

An apparatus for use in providing free-space optical communication, comprising:

• a optical beam transmitter configured to generate a narrow diverging transmit beam;
• an optical receiver having a narrow field of view, wherein the narrow field of view is less than the divergence of the transmit beam;
• and
• a controller coupled with the optical receiver, wherein the controller is configured to determine a power level of a receive beam and further configured to determine adjustments to a direction of transmission such that a maximum receive power is detected;
• wherein the optical receiver and optical beam transmitter are included in a first link head that is movable such that the optical receiver and optical beam transmitter are moved to maximize the receive power from a second link head;
• wherein both the first and second link heads are capable of moving to maximize receive power levels at a same time and without having to communicate alignment information between them;
• wherein the optical receiver is further configured with a multi-region field of view.