US 11,777,603 B2
High magnification afocal telescope with high index field curvature corrector
Nam-hyong Kim, San Jose, CA (US); Andrei Kazmierski, Pleasanton, CA (US); and Devin Brinkley, Redwood City, CA (US)
Assigned to X Development LLC, Mountain View, CA (US)
Filed by X DEVELOPMENT LLC, Mountain View, CA (US)
Filed on Jun. 10, 2019, as Appl. No. 16/436,278.
Claims priority of provisional application 62/793,135, filed on Jan. 16, 2019.
Prior Publication US 2020/0228202 A1, Jul. 16, 2020
Int. Cl. H04B 10/112 (2013.01); H04B 10/116 (2013.01); G02B 27/00 (2006.01); H04B 10/40 (2013.01); G02B 5/20 (2006.01); G02B 13/14 (2006.01)
CPC H04B 10/116 (2013.01) [G02B 5/208 (2013.01); G02B 13/14 (2013.01); G02B 27/0025 (2013.01); H04B 10/112 (2013.01); H04B 10/1123 (2013.01); H04B 10/1125 (2013.01); H04B 10/40 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A free-space optical communication system comprising:
a first lens group having a positive power that is configured to receive a communication signal from a remote free-space optical transmitter, the first lens group having a first focal plane;
a single field corrector lens having a negative power that is positioned between the first lens group and the first focal plane of the first lens group and positioned closer to the first focal plane than to the first lens group, the single field corrector lens comprising:
(i) material having an index of refraction of at least 2.0,
(ii) an input side that includes a concave surface, and
(iii) an output side that includes a convex surface having a second radius of curvature,
wherein the single field corrector lens is configured to correct a field curvature caused by the first lens group, and a combination of the first lens group and the single field corrector lens has a second focal plane that is farther from the first lens group than is the first focal plane;
a second lens group positioned with the second focal plane between the single field corrector lens and the second lens group and configured to couple the communication signal to a sensor of the free-space optical communication system, and wherein the single field corrector lens has a smaller diameter than lenses in the first lens group and the second lens group;
the sensor; and
one or more processors configured to:
extract data related to the communication signal using the sensor; and
adjust at least one of pointing direction, power, bit rate, or encoding scheme of the system according to the extracted data.