Free-space optical communication system employing wavelength conversion

An apparatus for communicating optical signals over a free-space link, comprising:

• means for receiving a first optical signal having a fiber interface fundamental wavelength from a first single mode optical fiber;
• a transmit wavelength transformer configured to convert the fiber interface fundamental wavelength of the first optical signal to a free-space fundamental wavelength;
• a transmitting element configured to direct the first optical signal having the free-space fundamental wavelength over the free-space link;
• a receiving element configured to receive a second optical signal having the free-space fundamental wavelength from the free-space link;
• a receive wavelength transformer configured to convert the free-space fundamental wavelength of the second optical signal to a fiber interface fundamental wavelength;
• and
• means for directing the second optical signal having the fiber interface fundamental wavelength into a second single mode optical fiber.

A method of communicating optical signals over a free-space link, comprising the steps of:

• receiving a first optical signal having a fiber interface fundamental wavelength from a first single mode optical fiber;
• amplifying the first optical signal with a multi-wavelength optical amplifier connected in-line with the first single mode optical fiber;
• attenuating the first optical signal with a variable optical attenuator that is optically coupled to the multi-wavelength optical amplifier;
• converting the fiber interface fundamental wavelength of the first optical signal to a free-space fundamental wavelength with a transmit wavelength transformer;
• and
• directing the first optical signal having the free-space fundamental wavelength over the free-space link.

An apparatus for communicating optical signals over a free-space link, comprising:

• means for receiving a first optical signal having a fiber interface fundamental wavelength from a first single mode optical fiber;
• a multi-wavelength optical amplifier connected in-line with the first single mode optical fiber for amplifying the first optical signal;
• a variable optical attenuator that is optically coupled to the multi-wavelength optical amplifier for attenuating the first optical signal;
• a transmit wavelength transformer configured to convert the fiber interface fundamental wavelength of the first optical signal to a free-space fundamental wavelength;
• and
• one or more transmitting elements configured to direct the first optical signal having the free-space fundamental wavelength over the free-space link.

A method of communicating optical signals over a free-space link, comprising the steps of:

• receiving a first optical signal having the free-space fundamental wavelength from the free-space link;
• converting the free-space fundamental wavelength of the first optical signal to a fiber interface fundamental wavelength with a receive wavelength transformer;
• amplifying the first optical signal with a multi-wavelength optical amplifier optically coupled to the receive wavelength transformer;
• attenuating the first optical signal with a variable optical attenuator that is optically coupled to the multi-wavelength optical amplifier;
• and
• directing the first optical signal having the fiber interface fundamental wavelength into a first single mode optical fiber.

An apparatus for communicating optical signals over a free-space link, comprising:

• a receiving element configured to receive a first optical signal having the free-space fundamental wavelength from the free-space link;
• a receive wavelength transformer configured to convert the free-space fundamental wavelength of the first optical signal to a fiber interface fundamental wavelength;
• a multi-wavelength optical amplifier optically coupled to the receive wavelength transformer for amplifying the first optical signal;
• a variable optical attenuator that is optically coupled to the multi-wavelength optical amplifier for attenuating the first optical signal;
• and
• means for directing the first optical signal having the fiber interface fundamental wavelength into a first single mode optical fiber.