Self forming waveguides for optical coupling and methodologies for making same
Systems and methods of forming an optical coupling between two optical waveguides where at least one of the optical waveguides is non-UV transmissive are disclosed. In one aspect, a self-forming waveguide (SFWG) is formed in a photosensitive material disposed between a UV transmissive optical waveguide and a non-UV transmissive component at least in part by a portion of an incident UV beam reflected from an interface between the photosensitive material and the non-UV transmissive material. In another aspect, two separate SFWG waveguides are formed in two separate photosensitive materials by UV beams passed thereto via a UV transmissive bridge waveguide.
1. A coupled optical system comprising:
a UV transmissive optical waveguide;
a non-UV transmissive optical waveguide;
a self-forming waveguide (SFWG) disposed between the UV transmissive optical waveguide and the non-UV transmissive optical waveguide; and
wherein the SFWG comprises an inner region and an outer region surrounding at least part of the inner region, the inner region having a higher refractive index than the outer region.
2. The coupled optical system according to claim 1 , wherein the inner region has the higher refractive index as a result of having received a higher amount of UV exposure than the outer region during formation of the SFWG.
3. The coupled optical system according to claim 2 , wherein the non-transmissive optical waveguide includes a core region terminating at an inner facet and a cladding region terminating at an outer facet, the SFWG having been formed at least in part by a UV beam reflected from the inner facet.
4. The coupled optical system according to claim 1 , wherein a separation distance between the UV transmissive optical waveguide and the non-UV transmissive optical waveguide is in the range between about 10 microns to about 100 microns.
5. The coupled optical system according to claim 1 , wherein the UV transmissive optical waveguide and the non-UV transmissive optical waveguide are transmissive to signals of interest.
6. The coupled optical system according to claim 1 , wherein the non-UV transmissive optical waveguide is an electro-absorption modulator (EAM), a laser, or a filter.
7. The coupled optical system according to claim 1 , wherein the SFWG allows an optical signal to pass between the UV transmissive optical waveguide and the non-UV transmissive optical waveguide with coupling losses no more than about 0.5 dB.
8. A coupled optical system comprising:
a first non-ultraviolet (UV) transmissive optical waveguide;
a second non-UV transmissive optical waveguide;
a UV transmissive bridge comprising a bridge waveguide disposed between the first and second optical waveguides;
a first self-forming waveguide (SFWG) disposed between the bridge waveguide and the first optical waveguide, wherein the first SFWG comprises a first inner region and a first outer region surrounding at least part of the first inner region, the first inner region having a higher refractive index than the first outer region; and
a second SFWG disposed between the bridge waveguide and the second optical waveguide, wherein the second SFWG comprises a second inner region and a second outer region surrounding at least part of the second inner region, the second inner region having a higher refractive index than the second outer region.
9. The coupled optical system according to claim 8 , wherein at least one of the first and second inner regions has the higher refractive relative to the corresponding first or second outer region index.
10. The coupled optical system according to claim 8 , wherein a separation distance between each of the first and second optical waveguides and the bridge waveguide is in the range between about 10 microns to about 100 microns.
11. The coupled optical system according to claim 8 , wherein the first and second optical waveguides are non-UV transmissive optical waveguides.
12. The coupled optical system according to claim 8 , wherein at least one of the first and second optical waveguides is an electro-absorption modulator (EAM), a laser, or a filter.
13. The coupled optical system according to claim 8 , wherein the UV transmissive bridge further comprises a UV input port for receiving an incident UV beam during formation of the first and second SFWGs.