US 11,988,873 B2
End structure of a waveguide
Katsuhiko Hirabayashi, Musashino (JP); Satomi Katayose, Musashino (JP); Yuji Fujiwara, Musashino (JP); and Ryoichi Kasahara, Musashino (JP)
Assigned to NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
Appl. No. 17/422,387
Filed by Nippon Telegraph and Telephone Corporation, Tokyo (JP)
PCT Filed Jan. 15, 2020, PCT No. PCT/JP2020/000956
§ 371(c)(1), (2) Date Jul. 12, 2021,
PCT Pub. No. WO2020/149278, PCT Pub. Date Jul. 23, 2020.
Claims priority of application No. 2019-005303 (JP), filed on Jan. 16, 2019.
Prior Publication US 2022/0091339 A1, Mar. 24, 2022
Int. Cl. G02B 6/30 (2006.01); G02B 6/26 (2006.01); G02B 6/32 (2006.01)
CPC G02B 6/30 (2013.01) [G02B 6/262 (2013.01); G02B 6/32 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An end portion structure of a transmission line configured to pass through light having a wavelength from a visible light region to an ultraviolet region, the end portion structure of the transmission line being connected with no adhesive located at a portion configured to pass through the light, the end portion structure comprising:
a first protective film comprising nitride, oxide, or fluoride and having a thickness in a range from 0.5 to 3 μm, the first protective film being located on an end surface of the transmission line at the end portion; and
one or more grooves that form gaps in the first protective film such that the first protective film is not continuous across the end surface.