US 11,862,923 B2
High cladding power mode field adapter for kilowatt fiber lasers
Gongwen Zhu, San Jose, CA (US); and Guan Sun, San Jose, CA (US)
Assigned to Lumentum Operations LLC, San Jose, CA (US)
Filed by Lumentum Operations LLC, San Jose, CA (US)
Filed on Feb. 1, 2022, as Appl. No. 17/649,635.
Claims priority of provisional application 63/264,431, filed on Nov. 22, 2021.
Prior Publication US 2023/0161099 A1, May 25, 2023
Int. Cl. G02B 6/14 (2006.01); G02B 6/255 (2006.01); G02B 6/26 (2006.01); G02B 6/42 (2006.01); H01S 3/067 (2006.01); G02B 6/02 (2006.01); H01S 3/094 (2006.01); G02B 6/036 (2006.01); G02B 6/122 (2006.01)
CPC H01S 3/06745 (2013.01) [G02B 6/14 (2013.01); G02B 6/2552 (2013.01); G02B 6/262 (2013.01); G02B 6/4296 (2013.01); H01S 3/06733 (2013.01); H01S 3/06754 (2013.01); G02B 6/02004 (2013.01); G02B 6/02376 (2013.01); G02B 6/036 (2013.01); G02B 6/1228 (2013.01); G02B 6/2558 (2013.01); H01S 3/094007 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A mode field adapter, comprising:
a first fiber including a core associated with a fundamental mode field diameter and a cladding, surrounding the core of the first fiber, with a diameter that decreases toward a waist of the first fiber, wherein the cladding surrounding the core of the first fiber is adiabatically etched such that a ratio between the core of the first fiber and the cladding surrounding the core changes over a length of the first fiber; and
a second fiber including a core associated with a fundamental mode field diameter that matches the fundamental mode field diameter of the first fiber at a waist of the second fiber and a cladding, surrounding the core of the second fiber, with a diameter that matches the diameter of the cladding of the first fiber at the waist of the second fiber and increases from the waist of the second fiber, wherein the core and the cladding surrounding the core of the second fiber are adiabatically tapered such that a ratio between the core of the second fiber and the cladding surrounding the core of the second fiber is constant over a length of the second fiber.