Abstract

Low-loss silica-based SiO2-Ta2O5 waveguides with an extremely high refractive index difference (Δ) are realized, while avoiding Ta2O5 crystallization. First, we determined in detail the thermal conditions needed for thermal treatment in a film-refinement process after the deposition of extremely high-Δ SiO2-Ta2O5 thin films to suppress Ta2O5 crystallization. Moreover, we confirmed that the crystallization of Ta2O5 was prompted mainly by the diffusion of boron (B) and phosphorus (P) dopants from the overcladding layer into the SiO2-Ta2O5 core region of the waveguide during the embedding process. By suppressing the diffusion of the B and P dopants from the overcladding layer using the double-layer cladding technique, we successfully fabricated extremely high-Δ waveguides and achieved a propagation loss of as low as 0.06 dB/cm. Extremely high-Δ waveguides appear to be a promising technology with which to realize high-density optically integrated and low-cost optical devices.

© 2014 IEEE

PDF Article

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription