公开(公告)号：US09755739B1

公开(公告)日：2017-09-05

申请号：US15171348

申请日：2016-06-02

Applicant: Google Inc.

Inventor： Chiachi Wang ,  Michael Sholl

IPC: G02B26/00 ,  G02B6/42 ,  G02B6/26 ,  G02B6/28 ,  H04B10/11 ,  H04B10/2581 ,  H04B10/50 ,  G02B6/036 ,  G02B27/09 ,  G02B6/34

CPC classification number: H04B10/11 ,  G02B6/03622 ,  G02B6/34 ,  G02B27/0927 ,  H04B10/1127 ,  H04B10/118 ,  H04B10/2581 ,  H04B10/503

Abstract: A method of free-space optical communication includes guiding, by focusing optics, an optical communication beam emitted from an optical transmitter into a double-clad optical fiber. The optical communication beam carrying data. The double-clad optical fiber has first and second ends, where the first end is arranged to receive the optical communication beam. The double-clad optical fiber includes a fiber core, a first cladding, and a second cladding. The method also includes directing, by collimating optics, the optical communication beam from the second end of the double-clad optical fiber toward an optical receiver of a communication terminal. the second portion of the optical communication beam arranged concentrically around the first portion of the optical communication beam, the first portion of the optical communication beam having a higher intensity than the second portion of the optical communication beam.

公开(公告)号：US20170339695A1

公开(公告)日：2017-11-23

申请号：US15156459

申请日：2016-05-17

Applicant: Google Inc.

Inventor： Chiachi Wang ,  Sheng-Hui Yang ,  Romain Clement ,  Michael Sholl

IPC: H04W72/04 ,  H04B7/185

CPC classification number: H04W72/0453 ,  H04B7/18513 ,  H04B10/1123

Abstract: A method includes receiving a first optical signal at a first communication terminal from a second communication terminal through a free space optical link. The received optical signal contains a modulated unique frequency tone. The method also includes mixing the modulated unique frequency tone with a reference signal to provide a mixed output signal and determining a signal strength of the modulated unique frequency tone based on the mixed output signal. The reference signal includes a same frequency as the modulated unique frequency tone. The method adjusts an optical head of the first communication terminal to establish acquisition and optical beam pointing with the second communication terminal based on the signal strength of the modulated unique frequency tone received from the second communication terminal.