Axial alignment of a lensed fiber in a silica v-groove
A v-groove assembly is used to edge couple a lensed fiber (e.g., an optical fiber made of silica) with a waveguide in a photonic chip. The v-groove assembly is made from fused silica. Fused silica is used to so that an adhesive (e.g., epoxy resin) used in bonding the lensed fiber to the v-groove assembly and/or bonding the v-groove assembly to the photonic chip can be cured, at least partially, by light.
1. A method for aligning an optical fiber with a v-groove assembly, the method comprising:
placing a facet of the v-groove assembly next to a mirror;
placing a first end of the optical fiber in a v-groove of the v-groove assembly, wherein the v-groove assembly comprises a base and a lid;
placing the lid over the optical fiber so that the optical fiber is between the base and the lid;
applying an adhesive to the v-groove assembly and/or the optical fiber for bonding the optical fiber to the v-groove assembly;
connecting a second end of the optical fiber to a splitter, wherein the splitter is optically coupled with an optical source and a detector;
transmitting light of a first wavelength from the optical source, through the splitter, to the optical fiber, and out the optical fiber through a tip of the first end of the optical fiber;
reflecting, with the mirror, light of the first wavelength from the tip of the optical fiber back into the optical fiber through the tip;
transmitting light of the first wavelength from the tip to the detector through the splitter;
receiving feedback from the detector;
adjusting a distance between the tip of the optical fiber and the mirror based on feedback from the detector;
at least partially curing the adhesive using light of a second wavelength passing through the lid, after adjusting the distance between the tip of the optical fiber and the mirror.
2. The method for aligning the optical fiber with the v-groove assembly as recited in claim 1 , wherein the lid is made of fused silica.
3. The method for aligning the optical fiber with the v-groove assembly as recited in claim 1 , wherein the base is made of fused silica.
4. The method for aligning the optical fiber with the v-groove assembly as recited in claim 1 , wherein light of the first wavelength is infrared light and light of the second wavelength is ultraviolet light.
5. The method for aligning the optical fiber with the v-groove assembly as recited in claim 1 , wherein adjusting the distance between the tip of the optical fiber and the mirror includes moving the optical fiber in an axial direction to optimize received power at the detector.
6. The method for aligning the optical fiber with the v-groove assembly as recited in claim 1 , further comprising bonding the v-groove assembly to a chip, after at least partially curing the adhesive.
7. The method for aligning the optical fiber with the v-groove assembly as recited in claim 6 , wherein the chip comprises crystalline silicon.
8. The method for aligning the optical fiber with the v-groove assembly as recited in claim 6 , wherein the chip comprises III-V material.
9. The method for aligning the optical fiber with the v-groove assembly as recited in claim 1 , wherein the adhesive is an epoxy resin configured to be at least partially cured by ultraviolet light.
10. The method for aligning the optical fiber with the v-groove assembly as recited in claim 1 , wherein the method further comprises transmitting the light of the first wavelength from the optical source and through an optical isolator before reflecting, with the mirror, light of the first wavelength from the tip of the optical fiber.