US 11,947,160 B2
Laser system using low-chlorine hollow core optical fiber
Jens Kristian Lyngsø, Copenhagen (DK); Christian Jakobsen, Virum (DK); Jesper Skov Gretlund, Copenhagen (DK); and Harald R. Simonsen, Lejre (DK)
Assigned to NKT PHOTONICS A/S, Birkerod (DK)
Filed by NKT Photonics A/S, Birkerød (DK)
Filed on Jan. 5, 2023, as Appl. No. 18/150,486.
Application 18/150,486 is a continuation of application No. 17/845,358, filed on Jun. 21, 2022, granted, now 11,573,366.
Application 17/845,358 is a continuation of application No. 12/717,509, filed on Mar. 4, 2010, granted, now 11,402,572, issued on Aug. 2, 2022.
Claims priority of provisional application 61/157,422, filed on Mar. 4, 2009.
Prior Publication US 2023/0161100 A1, May 25, 2023
Int. Cl. G02B 6/02 (2006.01); C03B 37/012 (2006.01); C03C 13/04 (2006.01); C03C 25/66 (2006.01)
CPC G02B 6/02342 (2013.01) [C03B 37/0122 (2013.01); C03C 13/045 (2013.01); C03C 25/66 (2013.01); C03B 2201/03 (2013.01); C03B 2201/20 (2013.01); C03B 2201/21 (2013.01); C03B 2203/14 (2013.01); C03B 2203/16 (2013.01); C03B 2203/42 (2013.01); G02B 6/02352 (2013.01); G02B 6/02357 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A laser system comprising a hollow core optical fiber, said optical fiber having an axial direction and a cross section perpendicular to said axial direction, said optical fiber comprising:
a hollow core region,
an inner cladding region surrounding said core region, and
an end facet at an end of the optical fiber,
where at least a portion of the optical fiber is comprised of a first type of feature comprising a void and a surrounding first silica material, said first type of feature extending along at least a part of said axial direction, said first silica material having a first chlorine concentration, c1, of about 300 ppm or less, providing that diffusion of chlorine to the end facet and resulting chlorine-induced degradation of the fiber end facet is mitigated.