US 9,810,842 B2
Substrate-type optical waveguide element
Akira Oka, Sakura (JP)
Assigned to FUJIKURA LTD., Tokyo (JP)
Filed by FUJIKURA LTD., Tokyo (JP)
Filed on Mar. 2, 2017, as Appl. No. 15/447,615.
Application 15/447,615 is a continuation of application No. PCT/JP2016/051375, filed on Jan. 19, 2016.
Claims priority of application No. 2015-008118 (JP), filed on Jan. 19, 2015.
Prior Publication US 2017/0176677 A1, Jun. 22, 2017
This patent is subject to a terminal disclaimer.
Int. Cl. G02F 1/035 (2006.01); G02B 6/126 (2006.01); G02B 6/125 (2006.01); G02B 6/14 (2006.01); G02F 1/01 (2006.01); G02B 6/122 (2006.01); G02B 6/27 (2006.01); H04J 14/06 (2006.01)
CPC G02B 6/126 (2013.01) [G02B 6/122 (2013.01); G02B 6/125 (2013.01); G02B 6/1228 (2013.01); G02B 6/14 (2013.01); G02B 6/2773 (2013.01); G02F 1/01 (2013.01); G02F 1/011 (2013.01); G02F 2203/07 (2013.01); H04J 14/06 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A substrate-type optical waveguide element comprising:
a lower cladding;
a core on the lower cladding, the core including a first core and a second core arranged side by side and a third core having an entrance edge surface connected to emission edge surfaces of the first core and the second core; and
an upper cladding on the lower cladding, the upper cladding covering the core,
the first core and the second core being arranged side by side in a side-by-side arrangement section that is started in a starting point corresponding to entrance edge surfaces of the first core and the second core and is ended in an ending point corresponding to the emission edge surfaces of the first core and the second core,
an effective refractive index of a TE0 polarized wave guided through the first core in the absence of the second core being lower than an effective refractive index of a TE0 polarized wave guided through the second core in the absence of the first core, each of the effective refractive indexes being observed in the starting point of the side-by -side arrangement section.
an effective refractive index of a TM0 polarized wave guided through the first core in the absence of the second core and the effective refractive index of the TE0 polarized wave guided through the second core in the absence of the first core being continuous as a function of a distance from the starting point of the side-by-side arrangement section,
a magnitude relationship between an effective refractive index of an odd mode of a TE0 polarized wave guided through the core and an effective refractive index of an even mode of a TM0 polarized wave guided through the core being reversed between the starting point and the ending point of the side-by-side arrangement section,
a refractive index distribution in a cross-section of the substrate-type optical waveguide element being vertically asymmetrical, the cross-section being perpendicular to a traveling direction of light guided through the core, the cross-section being in an interaction section, in which the odd mode of the TE0 polarized wave guided through the core and the even mode of the TM0 polarized wave guided through the core interact with each other.