Free-space optical communication apparatus and method for controlling free-space optical communication apparatus

A method for controlling a free-space optical communication apparatus, the free-space optical communication apparatus comprising:

• a light emission section configured to emit light;
• an optical phase modulation section configured to adjust a direction of the light emitted by the light emission section;
• and
• a light reception section configured to receive light from outside, the method comprising:
• a communication control process comprising, by causing the light emission section to emit first communication light to a first adjusted direction and causing the light reception section to receive second communication light from a communication counterpart, carrying out free-space optical communication with the communication counterpart;
• and
• a measurement control process comprising measuring a distance to a surrounding object by causing the light emission section to emit pulsed light to a second adjusted direction and causing the light reception section to receive reflected light of the pulsed light,
• wherein, in the communication control process, by causing the optical phase modulation section to change a first light emission direction of the first communication light, detecting the first light emission direction in which free-space optical communication is possible with the communication counterpart,
• wherein information indicative of a second light emission direction of the second communication light from the communication counterpart is superimposed on the second communication light, and
• wherein in the measurement control process, an attitude of the communication counterpart is measured on a basis of the first light emission direction and the second light emission direction.