Single mode fiber-to-channel waveguide through-line coupler

DETAILED DESCRIPTION The coupling procedure is carried out in the following manner.
A capillary tube 10 is formed with a slotted end with the slots 11 and 12 perpendicular to each other.
Slot 11 is of greater length than slot 12, the purpose of which will be shown later.
The opposite end of the capillary tube is cut along the length on the same plane as slot 11 to provide a length 13 which is of semicylindrical shape.
One end of a piece of single-mode optical fiber 14, with both ends prepared by the score-and-breaking-under-tension method is inserted at the semicylindrical end of the capillary tube through the capillary tube and fixed in position at the semicylindrical end by use of a dissolvable wax 15.
The fiber 14 extends beyond the slotted end of the capillary tube so that the protruding end may be placed in an abutting position relative to one end of a channel waveguide 16 on a substrate 17.
The fiber-tube assembly is mounted on a micropositioner (not shown) such as a klinger differential screw translator which includes a XYZ translation stage with movement accuracy of less than 0.
4 .
mu.
m and two angular orientation adjustments.
The substrate 17 with the channel waveguide 15 on the surface thereof is prepared as by cleaving the ends or by carefully polishing the ends to form ends which are square and perpendicular to the channel waveguide axis.
A prism coupler is positioned adjacent the channel waveguide for coupling light from the channel waveguide during assembly.
The capillary tube with the single-mode optical fiber extending therethrough is arranged in a vertical position.
The channel waveguide is positioned in vertical alignment with the optical fiber and in an abutting position with respect to the end of the optical fiber.
A laser light is launched through an objective lens of a microscope into the end of the optical fiber on the semicylindrical end of the capillary tube.
The light output of the optical fiber is subsequently fed into the abutting channel waveguide and the light that passes through the channel waveguide and exits through the prism coupler is detected and measured