Optical time distributor and process for optical two-way time-frequency transfer

The optical time distributor of claim 15, further comprising:

• an optical synchronization verification 200 in optical communication with the master clock 110 and the remote clock 112 and that:
• receives the master clock coherent optical pulse train output 150 from the master clock 110;
• receives the remote clock coherent optical pulse train output 182 from the remote clock 112;
• and
• produces an out-of-loop verification 202 in response to receipt of the master clock coherent optical pulse train output 150 and the remote clock coherent optical pulse train output 182.

The optical time distributor of claim 15, further comprising:

• a pulse-per-second verification 204 in optical communication with the master clock 110 and the remote clock 112 and that:
• receives the master pulse-per-second output 157 from the master clock 110;
• receives the remote pulse-per-second output 195 from the remote clock 112;
• and
• produces an optical interference 206 in response to receipt of the master pulse-per-second output 157 and the remote pulse-per-second output 195.

The optical time distributor of claim 15, further comprising:

• a frequency verification 208 in electrical communication with the master clock 110 and the remote clock 112 and that:
• receives the master frequency output 151 from the master clock 110;
• receives the remote frequency output 181 from the remote clock 112;
• and
• produces a relative phase difference 210 in response to receipt of the master frequency output 151 and the remote frequency output 181.

An optical time distributor 100 for optical two-way time-frequency transfer, the optical time distributor 100 comprising:

• a master clock 110 comprising:
• a master comb 138 that receives a reference oscillator signal 144 from a first oscillator 142 and produces:
• a local master clock signal 146;
• a master clock coherent optical pulse train output 150;
• a master frequency output 151;
• a master pulse-per-second output 157;
• and
• a master coherent optical pulse train 148 in response to receipt of the reference oscillator signal 144;
• a transfer comb 134 that receives a reference oscillator signal 140 from the first oscillator 142 and produces, in response to receipt of the reference oscillator signal 140, a transfer coherent optical pulse train 136;
• a master-transfer optical transceiver 166 that:
• receives the master coherent optical pulse train 148 from the master comb 138;
• receives the transfer coherent optical pulse train 136 from the transfer comb 134;
• and
• produces a RF master-transfer interferogram 168 in response to receipt of the master coherent optical pulse train 148 and the transfer coherent optical pulse train 136;
• a remote-transfer optical transceiver 162 that:
• receives the transfer coherent optical pulse train 136 from the transfer comb 134;
• receives a remote coherent optical pulse train 176 from a remote comb 174;
• and
• produces a RF remote-transfer interferogram 164 in response to receipt of a remote optical signal 124 and the transfer coherent optical pulse train 136;
• a digital signal controller 152 in electrical communication with the master comb 138, the master-transfer optical transceiver 166, the remote-transfer optical transceiver 162, and a coarse timing and communications module 130 and that:
• receives the local master clock signal 146, the RF master-transfer interferogram 168, and the RF remote-transfer interferogram 164;
• receives a cw laser heterodyne signal 159;
• produces a cw laser modulation 156 and a pulse label 154 in response to receipt of the local master clock signal 146, the RF master-transfer interferogram 168, the RF remote-transfer interferogram 164, and the cw laser heterodyne signal 159;
• produces the master pulse-per-second output 157 via a pulse selector 155;
• and
• produces the pulse label 154;
• the coarse timing and communications module 130 in electrical communication with the digital signal controller 152 and that:
• generates the cw laser heterodyne signal 159 in response to receipt of a modulated cw laser signal 132;
• and
• receives the cw laser modulation 156 from the digital signal controller 152;
• and
• produces an outgoing modulated cw laser signal 132 in response to receipt of the cw laser modulation 156;
• a free-space optical terminal 114 in optical communication with the coarse timing and communications module 130, the transfer comb 134, and a free space link 400 and that:
• transfers the modulated cw laser signal 132 and the transfer coherent optical pulse train 136 from the master clock 110 to the free space link 400;
• transfers the remote optical signal 124 from the free space link 400 to the master clock 110;
• and
• produces a master optical signal 116 in response to receipt of the modulated cw laser signal 132 and the transfer coherent optical pulse train 136, the master optical signal 116 comprising:
• a transfer coherent optical pulse train 118;
• and
• a modulated cw laser signal 120;
• a remote clock 112 in optical communication with the master clock 110 via the free space link 400 and comprising:
• the remote comb 174 that receives a reference oscillator signal 196 from a second oscillator 194 and produces:
• a local remote clock signal 177;
• a remote clock coherent optical pulse train output 182;
• a remote frequency output 181;
• a remote pulse-per-second output 195;
• and
• the remote coherent optical pulse train 176 in response to receipt of the reference oscillator signal 196;
• a free-space optical terminal 122 in optical communication:
• with the remote comb 174;
• and
• with the master clock 110 via the free space link 400, and that receives:
• the remote coherent optical pulse train 176 from the remote comb 174;
• and
• the master optical signal 116 from the free-space optical terminal 114 of the master clock 110, and that communicates:
• the modulated cw laser signal 124 to the free-space optical terminal 114 of the master clock 110, the modulated cw laser signal 124 comprising:
• the remote coherent optical pulse train 126;
• and
• a modulated cw laser signal 127;
• a transfer-remote optical transceiver 184 that:
• receives the remote coherent optical pulse train 176 from the remote comb 174;
• receives the transfer coherent optical pulse train 118;
• and
• produces a RF transfer-remote interferogram 186 in response to receipt of the remote coherent optical pulse train 176 and the transfer coherent optical pulse train 118;
• a coarse timing and communications module 170 in electrical communication with a digital signal controller 188 and in optical communication with the free-space optical terminal 122;
• the digital signal controller 188 in electrical communication with the remote comb 174, the transfer-remote optical transceiver 184, and the coarse timing and communications module 170 and that:
• receives the local remote clock signal 177, and the RF transfer-remote interferogram 186 from the transfer-remote optical transceiver 184;
• receives a cw laser heterodyne signal 198;
• produces a cw laser modulation 199 and a pulse label 192;
• produces a remote pulse-per-second output 195 via a pulse selector 193;
• produces the pulse label pulse label 192;
• and
• produces a clock feedback signal 190 in response to receipt of the RF transfer-remote interferogram 186;
• the coarse timing and communications module 170 in electrical communication with the digital signal controller 188 and that:
• generates the cw laser heterodyne signal 198 in response to receipt of the incoming modulated cw laser signal 172;
• receives the cw laser modulation 199 from the digital signal controller 188;
• and
• produces an outgoing modulated cw laser signal 172 in response to receipt of the cw laser modulation 199.